Math and Stats Tools

• AbsoluteValue
• Add
• And
• Anova
• ArcCos
• ArcSin
• ArcTan
• Arcosh
• Arsinh
• Artanh
• Atan2
• AttributeCorrelation
• AttributeCorrelationNeighbourhoodAnalysis
• AttributeHistogram
• AttributeScattergram
• Ceil
• Cos
• Cosh
• CrispnessIndex
• CrossTabulation
• CumulativeDistribution
• Decrement
• Divide
• EqualTo
• Exp
• Exp2
• Floor
• GreaterThan
• ImageAutocorrelation
• ImageCorrelation
• ImageCorrelationNeighbourhoodAnalysis
• ImageRegression
• InPlaceAdd
• InPlaceDivide
• InPlaceMultiply
• InPlaceSubtract
• Increment
• IntegerDivision
• InversePrincipalComponentAnalysis
• IsNoData
• KappaIndex
• KsTestForNormality
• LessThan
• ListUniqueValues
• Ln
• Log10
• Log2
• Max
• Min
• Modulo
• Multiply
• Negate
• Not
• NotEqualTo
• Or
• PairedSampleTTest
• PhiCoefficient
• Power
• PrincipalComponentAnalysis
• Quantiles
• RandomField
• RandomSample
• RasterHistogram
• RasterSummaryStats
• Reciprocal
• RescaleValueRange
• RootMeanSquareError
• Round
• Sin
• Sinh
• Square
• SquareRoot
• Subtract
• Tan
• Tanh
• ToDegrees
• ToRadians
• TrendSurface
• TrendSurfaceVectorPoints
• Truncate
• TurningBandsSimulation
• TwoSampleKsTest
• WilcoxonSignedRankTest
• Xor
• ZScores
• ZonalStatistics

AbsoluteValue

This tool creates a new raster (--output) in which each grid cell is equal to the absolute value of the corresponding grid cell in an input raster (--input). The absolute value is a number that is equal in magnitude but is always positive.

See Also: Negate

Parameters:

Python function:

wbt.absolute_value(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=AbsoluteValue -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: July 5, 2017

Last Modified: 12/10/2018

Add

This tool creates a new raster in which each grid cell is equal to the addition of the corresponding grid cells in two input rasters or one input raster and a constant value. If two images are input, both images must possess the same number of rows and columns and spatial extent, as the analysis will be carried out on a cell-by-cell basis. If a grid cell contains a NoData value in either of the input images, the cell will be excluded from the analysis.

See Also: Subtract, Multiply, Divide, InPlaceAdd

Parameters:

Python function:

wbt.add(
    input1, 
    input2, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Add -v --wd="/path/to/data/" ^
--input1='in1.tif' --input2='in2.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 05/07/2017

Last Modified: 24/01/2019

And

This tool is a Boolean AND operator, i.e. it works on True or False (1 and 0) values. Grid cells for which the first and second input rasters (--input1; --input2) have True values are assigned 1 in the output raster, otherwise grid cells are assigned a value of 0. All non-zero values in the input rasters are considered to be True, while all zero-valued grid cells are considered to be False. Grid cells containing NoData values in either of the input rasters will be assigned a NoData value in the output raster (--output).

See Also: Not, Or, Xor

Parameters:

Python function:

wbt.And(
    input1, 
    input2, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=And -v --wd="/path/to/data/" ^
--input1='in1.tif' --input2='in2.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 01/07/2017

Last Modified: 12/10/2018

Anova

This tool performs an Analysis of variance (ANOVA) test on the distribution of values in a raster (--input) among a group of features (--features). The ANOVA report is written to an output HTML report (--output).

Parameters:

Python function:

wbt.anova(
    i, 
    features, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Anova -v --wd="/path/to/data/" ^
-i=data.tif --features=classes.tif -o=anova.html 

Source code on GitHub

Author: Dr. John Lindsay

Created: 23/09/2017

Last Modified: 12/10/2018

ArcCos

This tool creates a new raster (--output) in which each grid cell is equal to the inverse cosine of the corresponding grid cell in an input raster (--input). The output raster will contain angular data measured in radian, in the range [0, π] or NoData if the number is outside the range [-1, 1]. If desired, you can convert radians to degrees using the ToDegrees tool. Grid cells with NoData values in the input raster will be assigned NoData values in the output raster.

See Also: ArcSin, ArcTan, ToDegrees

Parameters:

Python function:

wbt.arc_cos(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=ArcCos -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 05/07/2017

Last Modified: 12/10/2018

ArcSin

This tool creates a new raster (--output) in which each grid cell is equal to the inverse sine of the corresponding grid cell in an input raster (--input). The output raster will contain angular data measured in radian, in the range [-π/2, π/2] or NoData if the number is outside the range [-1, 1]. If desired, you can convert radians to degrees using the ToDegrees tool. Grid cells with NoData values in the input raster will be assigned NoData values in the output raster.

See Also: ArcCos, ArcTan, ToDegrees

Parameters:

Python function:

wbt.arc_sin(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=ArcSin -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 05/07/2017

Last Modified: 12/10/2018

ArcTan

This tool creates a new raster (--output) in which each grid cell is equal to the inverse tangent of the corresponding grid cell in an input raster (--input). The output raster will contain angular data measured in radian, in the range [-π/2, π/2] or NoData if the number is outside the range [-1, 1]. If desired, you can convert radians to degrees using the ToDegrees tool. Grid cells with NoData values in the input raster will be assigned NoData values in the output raster.

See Also: ArcCos, ArcTan, Atan2, ToDegrees

Parameters:

Python function:

wbt.arc_tan(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=ArcTan -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 05/07/2017

Last Modified: 12/10/2018

Arcosh

This tool creates a new raster (--output) in which each grid cell is equal to the inverse hyperbolic cosine (arcosh) of the corresponding grid cell in an input raster (--input). The output raster will contain angular data measured in radian, in the range [0, π] or NoData if the number is outside the range [-1, 1]. If desired, you can convert radians to degrees using the ToDegrees tool. Grid cells with NoData values in the input raster will be assigned NoData values in the output raster.

See Also: Arsinh, Artanh, ToDegrees

Parameters:

Python function:

wbt.arcosh(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Arcosh -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 26/10/2019

Last Modified: 26/10/2019

Arsinh

This tool creates a new raster (--output) in which each grid cell is equal to the inverse hyperbolic sine (arsinh) of the corresponding grid cell in an input raster (--input). The output raster will contain angular data measured in radian, in the range [-π/2, π/2] or NoData if the number is outside the range [-1, 1]. If desired, you can convert radians to degrees using the ToDegrees tool. Grid cells with NoData values in the input raster will be assigned NoData values in the output raster.

See Also: Arcosh, Artanh, ToDegrees

Parameters:

Python function:

wbt.arsinh(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Arsinh -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 26/10/2019

Last Modified: 26/10/2019

Artanh

This tool creates a new raster (--output) in which each grid cell is equal to the inverse hyperbolic tangent (artanh) of the corresponding grid cell in an input raster (--input). The output raster will contain angular data measured in radian, in the range [-π/2, π/2] or NoData if the number is outside the range [-1, 1]. If desired, you can convert radians to degrees using the ToDegrees tool. Grid cells with NoData values in the input raster will be assigned NoData values in the output raster.

See Also: Arcosh, Arsinh, ToDegrees

Parameters:

Python function:

wbt.artanh(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Artanh -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 26/10/2019

Last Modified: 26/10/2019

Atan2

This tool creates a new raster (--output) in which each grid cell is equal to the four quadrant arctangent of an y (--input_y) and x (--input_x) inputs, measured in radians. Inputs may be either rasters or constant values. The output raster will contain angular data measured in radian, in the range:

x = 0, y = 0: 0
x >= 0: arctan(y/x) -> [-π/2, π/2]
y >= 0: arctan(y/x) + π -> (π/2, π]
y < 0: arctan(y/x) - π -> (-π, -π/2)

If desired, you can convert radians to degrees using the ToDegrees tool. Grid cells with NoData values in the input raster will be assigned NoData values in the output raster.

See Also: ArcCos, ArcTan, Atan2, ToDegrees

Parameters:

Python function:

wbt.atan2(
    input_y, 
    input_x, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Atan2 -v --wd="/path/to/data/" ^
--input_y='in1.tif' --input_x='in2.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 06/07/2017

Last Modified: 12/10/2018

AttributeCorrelation

This tool can be used to estimate the Pearson product-moment correlation coefficient (r) for each pair among a group of attributes associated with the database file of a shapefile. The r-value is a measure of the linear association in the variation of the attributes. The coefficient ranges from -1, indicated a perfect negative linear association, to 1, indicated a perfect positive linear association. An r-value of 0 indicates no correlation between the test variables.

Notice that this index is a measure of the linear association; two variables may be strongly related by a non-linear association (e.g. a power function curve) which will lead to an apparent weak association based on the Pearson coefficient. In fact, non-linear associations are very common among spatial variables, e.g. terrain indices such as slope and contributing area. In such cases, it is advisable that the input images are transformed prior to the estimation of the Pearson coefficient, or that an alternative, non-parametric statistic be used, e.g. the Spearman rank correlation coefficient.

The user must specify the name of the input vector Shapefile (--input). Correlations will be calculated for each pair of numerical attributes contained within the input file's attribute table and presented in a correlation matrix HMTL output (--output).

See Also: ImageCorrelation, AttributeScattergram, AttributeHistogram

Parameters:

Python function:

wbt.attribute_correlation(
    i, 
    output=None, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=AttributeCorrelation -v ^
--wd="/path/to/data/" -i=file.shp -o=outfile.html 

Source code on GitHub

Author: Dr. John Lindsay

Created: 29/04/2018

Last Modified: 12/10/2018

AttributeCorrelationNeighbourhoodAnalysis

This tool can be used to perform nieghbourhood-based (i.e. using roving search windows applied to each grid cell) correlation analysis on two continuous attributes (--field1 and --field2) of an input vector (--input). The tool outputs correlation value and a significance (p-value) fields (CORREL and PVALUE) to the input vector's attribute table. Additionally,the user must specify the size of the search window (--filter) and the correlation statistic (--stat). Options for the correlation statistic include pearson, kendall, and spearman. Notice that Pearson's r is the most computationally efficient of the three correlation metrics but is unsuitable when the input distributions are non-linearly associated, in which case, either Spearman's Rho or Kendall's tau-b correlations are more suited. Both Spearman and Kendall correlations evaluate monotonic associations without assuming linearity in the relation. Kendall's tau-b is by far the most computationally expensive of the three statistics and may not be suitable to larger sized search windows.

See Also: AttributeCorrelation, ImageCorrelationNeighbourhoodAnalysis

Parameters:

Python function:

wbt.attribute_correlation_neighbourhood_analysis(
    i, 
    field1, 
    field2, 
    radius=None, 
    min_points=None, 
    stat="pearson", 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=AttributeCorrelationNeighbourhoodAnalysis ^
-v --wd="/path/to/data/" -i=input.shp --field1=DEPEND ^
--field2=INDEPEND --radius=4.0 --min_points=3 ^
--stat="spearman" 

Source code on GitHub

Author: Simon Gudim and Dr. John Lindsay

Created: 19/12/2019

Last Modified: 10/01/2020

AttributeHistogram

This tool can be used to create a histogram, which is a graph displaying the frequency distribution of data, for the values contained in a field of an input vector's attribute table. The user must specify the name of an input vector (--input) and the name of one of the fields (--field) contained in the associated attribute table. The tool output (--output) is an HTML formated histogram analysis report. If the specified field is non-numerical, the tool will produce a bar-chart of class frequency, similar to the tabular output of the ListUniqueValues tool.

See Also: ListUniqueValues, RasterHistogram

Parameters:

Python function:

wbt.attribute_histogram(
    i, 
    field, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=AttributeHistogram -v ^
--wd="/path/to/data/" -i=lakes.shp --field=HEIGHT ^
-o=outfile.html 

Source code on GitHub

Author: Dr. John Lindsay

Created: 12/04/2018

Last Modified: 12/10/2018

AttributeScattergram

This tool can be used to create a scattergram for two numerical fields (--fieldx and --fieldy) contained within an input vector's attribute table (--input). The user must specify the name of an input shapefile and the name of two of the fields contained it the associated attribute table. The tool output (--output) is an HTML formated report containing a graphical scattergram plot.

See Also: AttributeHistogram, AttributeCorrelation

Parameters:

Python function:

wbt.attribute_scattergram(
    i, 
    fieldx, 
    fieldy, 
    output, 
    trendline=False, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=AttributeScattergram -v ^
--wd="/path/to/data/" -i=lakes.shp --fieldx=HEIGHT ^
--fieldy=area -o=outfile.html --trendline 

Source code on GitHub

Author: Dr. John Lindsay

Created: 12/04/2018

Last Modified: 18/10/2019

Ceil

This tool performs a ceiling (ceil) operation on the values in an input raster (--input) to the nearest integer value. The ceil function calculates the smallest integer greater than or equal to the input value (e.g. ceil(0.5) = 1, ceil(-4.5) = -5). The output raster (--output) will be of an I32 data type.

See Also: Round, Floor, Truncate

Parameters:

Python function:

wbt.ceil(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Ceil -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 05/07/2017

Last Modified: 26/10/2019

Cos

This tool creates a new raster (--output) in which each grid cell is equal to the cosine (cos) of the corresponding grid cell in an input raster (--input). The input raster image should contain angular data measured in radians. You may convert a raster containing degrees to radians using the ToRadians tool. Grid cells with NoData values in the input raster will be assigned NoData values in the output raster.

See Also: Sin, Tan, ArcCos, ToRadians

Parameters:

Python function:

wbt.cos(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Cos -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 05/07/2017

Last Modified: 12/10/2018

Cosh

This tool creates a new raster (--output) in which each grid cell is equal to the hyperbolic cosine (cosh) of the corresponding grid cell in an input raster (--input). The input raster image should contain angular data measured in radians. You may convert a raster containing degrees to radians using the ToRadians tool. Grid cells with NoData values in the input raster will be assigned NoData values in the output raster.

See Also: Sinh, Tanh, ToRadians

Parameters:

Python function:

wbt.cosh(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Cosh -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 06/07/2017

Last Modified: 12/10/2018

CrispnessIndex

The Crispness Index (C) provides a means of quantifying the crispness, or fuzziness, of a membership probability (MP) image. MP images describe the probability of each grid cell belonging to some feature or class. MP images contain values ranging from 0 to 1.

The index, as described by Lindsay (2006), is the ratio between the sum of the squared differences (from the image mean) in the MP image divided by the sum of the squared differences for the Boolean case in which the total probability, summed for the image, is arranged crisply.

C is closely related to a family of relative variation coefficients that measure variation in an MP image relative to the maximum possible variation (i.e. when the total probability is arranged such that grid cells contain only 1s or 0s). Notice that 0 < C < 1 and a low C-value indicates a nearly uniform spatial distribution of any probability value, and C = 1 indicates a crisp spatial probability distribution, containing only 1's and 0's.

C is calculated as follows:

C = SS_mp ∕ SS_B = [∑(pij − p-bar)^2] ∕ [ ∑pij(1 − p-bar)^2 + p2(RC − ∑pij)]

Note that there is an error in the original published equation. Specifically, the denominator read:

∑pij(1 - p_bar)^2 + p_bar^2 (RC - ∑pij)

instead of the original:

∑pij(1 - p_bar^2) - p_bar^2 (RC - ∑pij)

References:

Lindsay, J. B. (2006). Sensitivity of channel mapping techniques to uncertainty in digital elevation data. International Journal of Geographical Information Science, 20(6), 669-692.

Parameters:

Python function:

wbt.crispness_index(
    i, 
    output=None, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=CrispnessIndex -v --wd="/path/to/data/" ^
-i=input.tif
>>./whitebox_tools -r=CrispnessIndex -v ^
--wd="/path/to/data/" -o=crispness.html 

Source code on GitHub

Author: Dr. John Lindsay

Created: 15/08/2017

Last Modified: 12/10/2018

CrossTabulation

This tool can be used to perform a cross-tabulation on two input raster images (--i1 and --i2) containing categorical data, i.e. classes. It will output a contingency table in HTML format (--output). A contingency table, also known as a cross tabulation or crosstab, is a type of table that displays the multivariate frequency distribution of the variables. These tables provide a basic picture of the interrelation between two categorical variables and can help find interactions between them. CrossTabulation can provide useful information about the nature of land-use/land-cover (LULC) changes between two dates of classified multi-spectral satellite imagery. For example, the extent of urban expansion could be described using the information about the extent of pixels in an 'urban' class in Date 2 that were previously assigned to other classes (e.g. agricultural LULC categories) in the Date 1 imagery.

Both input images must share the same grid, as the analysis requires a comparison of a pair of images on a cell-by-cell basis. If a grid cell contains a NoData value in either of the input images, the cell will be excluded from the analysis.

Parameters:

Python function:

wbt.cross_tabulation(
    input1, 
    input2, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=CrossTabulation -v ^
--wd="/path/to/data/" --i1="file1.tif" --i2="file2.tif" ^
-o=outfile.html 

Source code on GitHub

Author: Dr. John Lindsay

Created: 18/12/2017

Last Modified: 12/10/2018

CumulativeDistribution

This tool converts the values in an input image (--input) into a cumulative distribution function. Therefore, the output raster (--output) will contain the cumulative probability value (0-1) of of values equal to or less than the value in the corresponding grid cell in the input image. NoData values in the input image are not considered during the transformation and remain NoData values in the output image.

See Also: ZScores

Parameters:

Python function:

wbt.cumulative_distribution(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=CumulativeDistribution -v ^
--wd="/path/to/data/" -i=DEM.tif -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 22/07/2017

Last Modified: 12/10/2018

Decrement

This tool can be used to decrease the values of each grid cell in an input raster (--input) by 1.0. Note that this tool will modify the input raster. If you would rather create a new raster file, leaving the input unmodified, use the Subtract tool instead.

See Also: InPlaceSubtract, Subtract, Increment

Parameters:

Python function:

wbt.decrement(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Decrement -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 11/07/2017

Last Modified: 12/10/2018

Divide

This tool creates a new raster in which each grid cell is equal to the division of the corresponding grid cells in two input rasters or one input raster and a constant value. If two images are input, both images must possess the same number of rows and columns and spatial extent, as the analysis will be carried out on a cell-by-cell basis. If a grid cell contains a NoData value in either of the input images, the cell will be excluded from the analysis.

See Also: Multiply, Add, Subtract, InPlaceDivide

Parameters:

Python function:

wbt.divide(
    input1, 
    input2, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Divide -v --wd="/path/to/data/" ^
--input1='in1.tif' --input2='in2.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 05/07/2017

Last Modified: 24/01/2019

EqualTo

This tool assigns grid cells for which both (--input1 and --input2) input rasters (or one raster and a constant value) have equal values a new value of 1 (True) in the output raster (--output). All non-equivalent grid cells are assigned a value of zero (False). Grid cells containing NoData values in either of the inputs will be assigned a NoData value in the output raster.

See Also: NotEqualTo, GreaterThan, LessThan

Parameters:

Python function:

wbt.equal_to(
    input1, 
    input2, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=EqualTo -v --wd="/path/to/data/" ^
--input1='in1.tif' --input2='in2.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 01/07/2017

Last Modified: 12/10/2018

Exp

This tool creates a new raster (--output) in which each grid cell is calculated as e to the power of the value of the corresponding grid cell in the input raster (--input). Moderate to large values in the input raster will result in very large values in the output raster and this may cause errors when you try to display the data. Grid cells with NoData values in the input raster will be assigned NoData values in the output raster.

See Also: Exp2, Power, Ln

Parameters:

Python function:

wbt.exp(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Exp -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 05/07/2017

Last Modified: 12/10/2018

Exp2

This tool creates a new raster (--output) in which each grid cell is calculated as 2 to the power of the value of the corresponding grid cell in the input raster (--input). Moderate to large values in the input raster will result in very large values in the output raster and this may cause errors when you try to display the data. Grid cells with NoData values in the input raster will be assigned NoData values in the output raster.

See Also: Exp, Power, Log2

Parameters:

Python function:

wbt.exp2(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Exp2 -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 06/07/2017

Last Modified: 12/10/2018

Floor

This tool performs a floor operation on the values in an input raster (--input) to the nearest integer value. The floor function calculates the largest integer less than or equal to the input value (e.g. floor(0.5) = 0, floor(-4.5) = -4). The output raster (--output) will be of an I32 data type.

See Also: Ceil, Round, Truncate

Parameters:

Python function:

wbt.floor(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Floor -v --wd="/path/to/data/" ^
-i='input.tif' -o='output.tif' 

Source code on GitHub

Author: Dr. John Lindsay

Created: 05/07/2017

Last Modified: 26/10/2019

GreaterThan

This tool assigns grid cells for which the first input raster or constant value (--input1) is greater than the second input raster or constant value (--input2) a new value of 1 (True) in the output raster (--output). All grid cells with lesser values are assigned a value of zero (False) in the output. Grid cells containing NoData values in either of the inputs will be assigned a NoData value in the output raster.

Use the --incl_equals flag to perform a greater-than-equal-to (>=) operation instead of the default greater-than (>) operator.

See Also: LessThan, EqualTo, NotEqualTo

Parameters:

Python function:

wbt.greater_than(
    input1, 
    input2, 
    output, 
    incl_equals=False, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=GreaterThan -v --wd="/path/to/data/" ^
--input1='in1.tif' --input2='in2.tif' -o=output.tif ^
--incl_equals 

Source code on GitHub

Author: Dr. John Lindsay

Created: 01/07/2017

Last Modified: 18/10/2019

ImageAutocorrelation

Spatial autocorrelation describes the extent to which a variable is either dispersed or clustered through space. In the case of a raster image, spatial autocorrelation refers to the similarity in the values of nearby grid cells. This tool measures the spatial autocorrelation of a raster image using the global Moran's I statistic. Moran's I varies from -1 to 1, where I = -1 indicates a dispersed, checkerboard type pattern and I = 1 indicates a clustered (smooth) surface. I = 0 occurs for a random distribution of values. ImageAutocorrelation computes Moran's I for the first lag only, meaning that it only takes into account the variability among the immediate neighbors of each grid cell.

The user must specify the names of one or more input raster images. In addition, the user must specify the contiguity type (--contiguity; Rook's, King's, or Bishop's), which describes which neighboring grid cells are examined for the analysis. The following figure describes the available cases:

Rook's contiguity

Kings's contiguity

Bishops's contiguity

The tool outputs an HTML report (--ouptut) which, for each input image (--input), reports the Moran's I value and the variance, z-score, and p-value (significance) under normal and randomization sampling assumptions.

Use the ImageCorrelation tool instead when there is need to determine the correlation among multiple raster inputs.

**NoData **values in the input image are ignored during the analysis.

See Also: ImageCorrelation, ImageCorrelationNeighbourhoodAnalysis

Parameters:

Python function:

wbt.image_autocorrelation(
    inputs, 
    output, 
    contiguity="Rook", 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=ImageAutocorrelation -v ^
--wd="/path/to/data/" -i="file1.tif, file2.tif, file3.tif" ^
-o=outfile.html --contiguity=Bishops 

Source code on GitHub

Author: Dr. John Lindsay

Created: 16/12/2017

Last Modified: 12/10/2018

ImageCorrelation

This tool can be used to estimate the Pearson product-moment correlation coefficient (r) between two or more input images (--inputs). The r-value is a measure of the linear association in the variation of the input variables (images, in this case). The coefficient ranges from -1.0, indicated a perfect negative linear association, to 1.0, indicated a perfect positive linear association. An r-value of 0.0 indicates no correlation between the test variables.

Note that this index is a measure of the linear association; two variables may be strongly related by a non-linear association (e.g. a power function curve) which will lead to an apparent weak association based on the Pearson coefficient. In fact, non-linear associations are very common among spatial variables, e.g. terrain indices such as slope and contributing area. In such cases, it is advisable that the input images are transformed prior to the estimation of the Pearson coefficient, or that an alternative, non-parametric statistic be used, e.g. the Spearman rank correlation coefficient.

The user must specify the names of two or more input images (--inputs). All input images must share the same grid, as the coefficient requires a comparison of a pair of images on a grid-cell-by-grid-cell basis. If more than two image names are selected, the correlation coefficient will be calculated for each pair of images and reported in the HTML output report (--output) as a correlation matrix. Caution must be exercised when attempted to estimate the significance of a correlation coefficient derived from image data. The very high N-value (essentially the number of pixels in the image pair) means that even small correlation coefficients can be found to be statistically significant, despite being practically insignificant.

NoData values in either of the two input images are ignored during the calculation of the correlation between images.

See Also: ImageCorrelationNeighbourhoodAnalysis, ImageRegression, ImageAutocorrelation

Parameters:

Python function:

wbt.image_correlation(
    inputs, 
    output=None, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=ImageCorrelation -v ^
--wd="/path/to/data/" -i="file1.tif, file2.tif, file3.tif" ^
-o=outfile.html 

Source code on GitHub

Author: Dr. John Lindsay

Created: 03/09/2017

Last Modified: 12/10/2018

ImageCorrelationNeighbourhoodAnalysis

This tool can be used to perform nieghbourhood-based (i.e. using roving search windows applied to each grid cell) correlation analysis on two input rasters (--input1 and --input2). The tool outputs a correlation value raster (--output1) and a significance (p-value) raster (--output2). Additionally, the user must specify the size of the search window (--filter) and the correlation statistic (--stat). Options for the correlation statistic include pearson, kendall, and spearman. Notice that Pearson's r is the most computationally efficient of the three correlation metrics but is unsuitable when the input distributions are non-linearly associated, in which case, either Spearman's Rho or Kendall's tau-b correlations are more suited. Both Spearman and Kendall correlations evaluate monotonic associations without assuming linearity in the relation. Kendall's tau-b is by far the most computationally expensive of the three statistics and may not be suitable to larger sized search windows.

See Also: ImageCorrelation, ImageRegression

Parameters:

Python function:

wbt.image_correlation_neighbourhood_analysis(
    input1, 
    input2, 
    output1, 
    output2, 
    filter=11, 
    stat="pearson", 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=ImageCorrelationNeighbourhoodAnalysis -v ^
--wd="/path/to/data/" --i1=file1.tif --i2=file2.tif ^
--o1=corr.tif --o2=sig.tif --stat="spearman" 

Source code on GitHub

Author: Simon Gudim and Dr. John Lindsay

Created: 06/12/2019

Last Modified: 06/12/2019

ImageRegression

This tool performs a bivariate linear regression analysis on two input raster images. The first image (--i1) is considered to be the independent variable while the second image (--i2) is considered to be the dependent variable in the analysis. Both input images must share the same grid, as the coefficient requires a comparison of a pair of images on a grid-cell-by-grid-cell basis. The tool will output an HTML report (--output) summarizing the regression model, an Analysis of Variance (ANOVA), and the significance of the regression coefficients. The regression residuals can optionally be output as a new raster image (--out_residuals) and the user can also optionally specify to standardize the residuals (--standardize).

Note that the analysis performs a linear regression; two variables may be strongly related by a non-linear association (e.g. a power function curve) which will lead to an apparently weak fitting regression model. In fact, non-linear relations are very common among spatial variables, e.g. terrain indices such as slope and contributing area. In such cases, it is advisable that the input images are transformed prior to the analysis.

NoData values in either of the two input images are ignored during the calculation of the correlation between images.

See Also: ImageCorrelation, ImageCorrelationNeighbourhoodAnalysis

Parameters:

Python function:

wbt.image_regression(
    input1, 
    input2, 
    output, 
    out_residuals=None, 
    standardize=False, 
    scattergram=False, 
    num_samples=1000, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=ImageRegression -v ^
--wd="/path/to/data/" --i1='file1.tif' --i2='file2.tif' ^
-o='outfile.html' --out_residuals='residuals.tif' ^
--standardize 

Source code on GitHub

Author: Dr. John Lindsay

Created: 27/09/2017

Last Modified: 18/10/2019

InPlaceAdd

This tool performs an in-place addition, or increment operation (i.e. input1 += input2). The user must specify the names of two input images (--input1 and --input2) and the tool will add the values of input2 to the input1 raster on a pixel-by-pixel basis. Therefore, the input1 raster is modified by this tool. Note that input2 may either be an existing raster file or a constant value. If input2 is a raster, it must have the same dimensions (rows and columns) as input1.

The difference between this tool and the Add tool is that Add does not modify either of its two operands, and instead creates a new output raster to save the resultant value into.

If input2 = 1, use the Increment tool instead.

See Also: Add, InPlaceSubtract, InPlaceDivide, InPlaceMultiply, Increment

Parameters:

Python function:

wbt.in_place_add(
    input1, 
    input2, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=InPlaceAdd -v --wd="/path/to/data/" ^
--input1='in1.tif' --input2='in2.tif'"
>>./whitebox_tools ^
-r=InPlaceAdd -v --wd="/path/to/data/" --input1='in1.tif' ^
--input2=10.5' 

Source code on GitHub

Author: Dr. John Lindsay

Created: 18/03/2018

Last Modified: 12/10/2018

InPlaceDivide

This tool performs an in-place division operation (i.e. input1 /= input2). The user must specify the names of two input images (--input1 and --input2) and the tool will divide the input1 raster by the input2 values on a pixel-by-pixel basis. Therefore, the input1 raster is modified by this tool. Note that input2 may either be an existing raster file or a non-zero constant value. If input2 is a raster, it must have the same dimensions (rows and columns) as input1. Zero-valued pixels in input2 will be assigned the NoData value in input1 after this operation.

The difference between this tool and the Divide tool is that Divide does not modify either of its two operands, and instead creates a new output raster to save the resultant value into.

See Also: Divide, InPlaceAdd, InPlaceMultiply, InPlaceSubtract

Parameters:

Python function:

wbt.in_place_divide(
    input1, 
    input2, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=InPlaceDivide -v --wd="/path/to/data/" ^
--input1='in1.tif' --input2='in2.tif'"
>>./whitebox_tools ^
-r=InPlaceDivide -v --wd="/path/to/data/" --input1='in1.tif' ^
--input2=10.5' 

Source code on GitHub

Author: Dr. John Lindsay

Created: 18/03/2018

Last Modified: 12/10/2018

InPlaceMultiply

This tool performs an in-place multiplication operation (i.e. input1 *= input2). The user must specify the names of two input images (--input1 and --input2) and the tool will multiply the input1 raster by the input2 values on a pixel-by-pixel basis. Therefore, the input1 raster is modified by this tool. Note that input2 may either be an existing raster file or a constant value. If input2 is a raster, it must have the same dimensions (rows and columns) as input1.

The difference between this tool and the Multiply tool is that Multiply does not modify either of its two operands, and instead creates a new output raster to save the resultant value into.

See Also: Multiply, InPlaceAdd, InPlaceDivide, InPlaceSubtract

Parameters:

Python function:

wbt.in_place_multiply(
    input1, 
    input2, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=InPlaceMultiply -v ^
--wd="/path/to/data/" --input1='in1.tif' ^
--input2='in2.tif'"
>>./whitebox_tools -r=InPlaceMultiply -v ^
--wd="/path/to/data/" --input1='in1.tif' --input2=10.5' 

Source code on GitHub

Author: Dr. John Lindsay

Created: 18/03/2018

Last Modified: 12/10/2018

InPlaceSubtract

This tool performs an in-place subtraction, or decrement operation (i.e. input1 -= input2). The user must specify the names of two input images (--input1 and --input2) and the tool will subtact the values of input2 from the input1 raster on a pixel-by-pixel basis. Therefore, the input1 raster is modified by this tool. Note that input2 may either be an existing raster file or a constant value. If input2 is a raster, it must have the same dimensions (rows and columns) as input1.

The difference between this tool and the Subtract tool is that Subtract does not modify either of its two operands, and instead creates a new output raster to save the resultant value into.

If input2 = 1, use the Decrement tool instead.

See Also: Subtract, InPlaceAdd, InPlaceDivide, InPlaceMultiply, Decrement

Parameters:

Python function:

wbt.in_place_subtract(
    input1, 
    input2, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=InPlaceSubtract -v ^
--wd="/path/to/data/" --input1='in1.tif' ^
--input2='in2.tif'"
>>./whitebox_tools -r=InPlaceSubtract -v ^
--wd="/path/to/data/" --input1='in1.tif' --input2=10.5' 

Source code on GitHub

Author: Dr. John Lindsay

Created: 18/03/2018

Last Modified: 12/10/2018

Increment

This tool can be used to increase the values of each grid cell in an input raster (--input) by 1.0. Note that this tool will modify the input raster. If you would rather create a new raster file, leaving the input unmodified, use the Add tool instead.

See Also: InPlaceAdd, Add, Decrement

Parameters:

Python function:

wbt.increment(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Increment -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 11/07/2017

Last Modified: 12/10/2018

IntegerDivision

This tool creates a new raster (--output) in which each grid cell is equal to the integer division of the corresponding grid cells in two input rasters or constant values (--input1 and --input2). The calculation differs from regular division in that the result is always an integer value (rounded by truncation). If the second raster / constant is zero the corresponding grid cell in the output raster will be assigned the NoData value. Grid cells containing NoData values in either of the inputs will be assigned a NoData value in the output raster.

See Also: Divide

Parameters:

Python function:

wbt.integer_division(
    input1, 
    input2, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=IntegerDivision -v ^
--wd="/path/to/data/" --input1='in1.tif' --input2='in2.tif' ^
-o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 06/07/2017

Last Modified: 12/10/2018

InversePrincipalComponentAnalysis

Note this tool is part of a WhiteboxTools extension toolset. Please contact Whitebox Geospatial Inc. for information about purchasing a license activation key (https://www.whiteboxgeo.com).

This tool takes a two or more component images (--inputs), and the principal component analysis (PCA) report derived using the PrincipalComponentAnalysis tool, and performs the inverse PCA transform to derive the original series of input images. This inverse transform is frequently performed to reduce noise within a multi-spectral image data set. With a typical PCA transform, high-frequency noise will commonly map onto the higher component images. By excluding one or more higher-valued component images from the input component list, the inverse transform can produce a set of images in the original coordinate system that exclude the information contained within component images excluded from the input list. Note that the number of output images will also equal the number of original images input to the PrincipalComponentAnalysis tool. The output images will be named automatically with a "inv_PCA_image" suffix.

See Also: PrincipalComponentAnalysis

Parameters:

Python function:

wbt.inverse_principal_component_analysis(
    inputs, 
    report, 
    callback=default_callback
)

Command-line Interface:

>> ./whitebox_tools -r=InversePrincipalComponentAnalysis ^
--inputs="PCA_comp1.tif; PCA_comp2.tif; PCA_comp3.tif" ^
--report=PCA_report.html 

Source code is unavailable due to proprietary license.

Author: Whitebox Geospatial Inc. (c)

Created: 14/03/2021

Last Modified: 14/03/2021

IsNoData

This tool can be used to identify areas of NoData values within an input image.The user must specify the name of the input and output (--input and --output) raster images. Grid cells containing the NoData value in the input image will be assigned a value of 1.0 in the output image. All non-NoData valued grid cells will be assigned 0.0 in the output image.

See Also: SetNodataValue, ConvertNodataToZero

Parameters:

Python function:

wbt.is_no_data(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=IsNoData -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 05/07/2017

Last Modified: 01/06/2020

KappaIndex

This tool calculates the Kappa index of agreement (KIA), or Cohen's Kappa, for two categorical input raster images (--input1 and --input2). The KIA is a measure of inter-rater reliability (i.e. classification accuracy) and is widely applied in many fields, notably remote sensing. For example, The KIA is often used as a means of assessing the accuracy of an image classification analysis. The KIA can be interpreted as the percentage improvement that the underlying classification has over and above a random classifier (i.e. random assignment to categories). The user must specify the output HTML file (--output). The input images must be of a categorical data type, i.e. contain classes. As a measure of classification accuracy, the KIA is more robust than the overall percent agreement because it takes into account the agreement occurring by chance. A KIA of 0 would indicate that the classifier is no better than random class assignment. In addition to the KIA, this tool will also output the producer's and user's accuracy, the overall accuracy, and the error matrix.

See Also: CrossTabulation

Parameters:

Python function:

wbt.kappa_index(
    input1, 
    input2, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=KappaIndex -v --wd="/path/to/data/" ^
--i1=class.tif --i2=reference.tif -o=kia.html 

Source code on GitHub

Author: Dr. John Lindsay

Created: 24/09/2017

Last Modified: 12/10/2018

KsTestForNormality

This tool will perform a Kolmogorov-Smirnov (K-S) test for normality to evaluate whether the frequency distribution of values within a raster image are drawn from a Gaussian (normal) distribution. The user must specify the name of the raster image. The test can be performed optionally on the entire image or on a random sub-sample of pixel values of a user-specified size. In evaluating the significance of the test, it is important to keep in mind that given a sufficiently large sample, extremely small and non-notable differences can be found to be statistically significant. Furthermore statistical significance says nothing about the practical significance of a difference.

See Also: TwoSampleKsTest

Parameters:

Python function:

wbt.ks_test_for_normality(
    i, 
    output, 
    num_samples=None, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=KsTestForNormality -v ^
--wd="/path/to/data/" -i=input.tif -o=output.html ^
--num_samples=1000
>>./whitebox_tools -r=KsTestForNormality -v ^
--wd="/path/to/data/" -i=input.tif -o=output.html 

Source code on GitHub

Author: Dr. John Lindsay

Created: 02/01/2018

Last Modified: 12/10/2018

LessThan

This tool assigns grid cells for which the first input raster or constant value (--input1) is less than the second input raster or constant value (--input2) a new value of 1 (True) in the output raster (--output). All grid cells with greater values are assigned a value of zero (False) in the output. Grid cells containing NoData values in either of the inputs will be assigned a NoData value in the output raster.

Use the --incl_equals flag to perform a less-than-equal-to (<=) operation instead of the default less-than (<) operator.

See Also: LessThan, EqualTo, NotEqualTo

Parameters:

Python function:

wbt.less_than(
    input1, 
    input2, 
    output, 
    incl_equals=False, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=LessThan -v --wd="/path/to/data/" ^
--input1='in1.tif' --input2='in2.tif' -o=output.tif ^
--incl_equals 

Source code on GitHub

Author: Dr. John Lindsay

Created: 01/07/2017

Last Modified: 18/10/2019

ListUniqueValues

This tool can be used to list each of the unique values contained within a categorical field of an input vector file's attribute table. The tool outputs an HTML formated report (--output) containing a table of the unique values and their frequency of occurrence within the data. The user must specify the name of an input shapefile (--input) and the name of one of the fields (--field) contained in the associated attribute table. The specified field should not contained floating-point numerical data, since the number of categories will likely equal the number of records, which may be quite large. The tool effectively provides tabular output that is similar to the graphical output provided by the AttributeHistogram tool, which, however, can be applied to continuous data.

See Also: AttributeHistogram

Parameters:

Python function:

wbt.list_unique_values(
    i, 
    field, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=ListUniqueValues -v ^
--wd="/path/to/data/" -i=lakes.shp --field=HEIGHT ^
-o=outfile.html 

Source code on GitHub

Author: Dr. John Lindsay

Created: 12/04/2018

Last Modified: 13/10/2018

Ln

This tool creates a new raster (--output) in which each grid cell is calculated as the base-e logarithm of the value of the corresponding grid cell in the input raster (--input), i.e. the natural logarithm. Eurler's number e is a constant approximately equal to 2.718282. Negative values in the input raster will be assigned the NoData value in the output raster. NoData values in the input image will be assigned the NoData value in the output image.

See Also: Log2, Log10, Exp

Parameters:

Python function:

wbt.ln(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Ln -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 06/07/2017

Last Modified: 13/10/2018

Log10

This tool creates a new raster (--output) in which each grid cell is calculated as the base-10 logarithm of the value of the corresponding grid cell in the input raster (--input). Negative values in the input raster will be assigned the NoData value in the output raster. NoData values in the input image will be assigned the NoData value in the output image.

See Also: Ln, Log2

Parameters:

Python function:

wbt.log10(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Log10 -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 06/07/2017

Last Modified: 13/10/2018

Log2

This tool creates a new raster (--output) in which each grid cell is calculated as the base-2 logarithm of the value of the corresponding grid cell in the input raster (--input). Negative values in the input raster will be assigned the NoData value in the output raster. NoData values in the input image will be assigned the NoData value in the output image.

See Also: Ln, Log10, Exp2

Parameters:

Python function:

wbt.log2(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Log2 -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 06/07/2017

Last Modified: 13/10/2018

Max

This tool performs a Max operation on either two input rasters or a raster and a constant value (--input1 and --input2). The operation is performed on a cell-by-cell basis, where by the output raster (--output) will be assigned the maximum value of each of the input values. NoData values in the input image will be assigned NoData values in the output raster.

See Also: Min

Parameters:

Python function:

wbt.max(
    input1, 
    input2, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Max -v --wd="/path/to/data/" ^
--input1='in1.tif' --input2='in2.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 06/07/2017

Last Modified: 13/10/2018

Min

This tool performs a Min operation on either two input rasters or a raster and a constant value (--input1 and --input2). The operation is performed on a cell-by-cell basis, where by the output raster (--output) will be assigned the minimum value of each of the input values. NoData values in the input image will be assigned NoData values in the output raster.

See Also: Max

Parameters:

Python function:

wbt.min(
    input1, 
    input2, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Min -v --wd="/path/to/data/" ^
--input1='in1.tif' --input2='in2.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 06/07/2017

Last Modified: 13/10/2018

Modulo

This tool creates a new raster (--output) in which each grid cell is equal to the remainder of the division of the corresponding grid cells in two input rasters or one input raster and a constant value (--input1 and --input2), i.e. it performs a modulo operation on two numbers. For example, the expression 14 Mod 4 equals 2. If either of the two input numbers is a floating-point value, the floating-point remainder of the division is returned. Because of the imprecision of floating-point storage, the Modulo tool can return an unexpected result when at least one of the operands is floating-point. If the second raster / constant is zero the corresponding grid cell in the output raster will be assigned the NoData value. NoData values in either of the input images will be assigned a NoData value in the output image. Notice that the IntegerDivision tool returns the integer quotient of a division. For example, the expression 14 intdiv 4 evaluates to 3.

See Also: IntegerDivision

Parameters:

Python function:

wbt.modulo(
    input1, 
    input2, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Modulo -v --wd="/path/to/data/" ^
--input1='in1.tif' --input2='in2.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 06/07/2017

Last Modified: 13/10/2018

Multiply

This tool creates a new raster in which each grid cell is equal to the multiplication (product) of the corresponding grid cells in two input rasters or one input raster and a constant value. If two images are input, both images must possess the same number of rows and columns and spatial extent, as the analysis will be carried out on a cell-by-cell basis. If a grid cell contains a NoData value in either of the input images, the cell will be excluded from the analysis.

See Also: Divide, Add, Subtract, InPlaceMulitply

Parameters:

Python function:

wbt.multiply(
    input1, 
    input2, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Multiply -v --wd="/path/to/data/" ^
--input1='in1.tif' --input2='in2.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 05/07/2017

Last Modified: 24/01/2019

Negate

This tool creates a new raster in which each grid cell is equal to negative one times the corresponding grid cell in the input raster. This effectively changes the sign of values. This tool also handles Boolean data (0, 1) by reversing values (i.e. 0->1 and 1->0).

See Also: AbsoluteValue

Parameters:

Python function:

wbt.negate(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Negate -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 06/07/2017

Last Modified: 13/10/2018

Not

This tool is a Boolean NOT operator, i.e. it works on True or False (1 and 0) values. Grid cells for which the first input raster (--input1) has a True value and the second raster (--input2) has a False value are assigned 0 in the output raster, otherwise grid cells are assigned a value of 0. All non-zero values in the input rasters are considered to be True, while all zero-valued grid cells are considered to be False. Grid cells containing NoData values in either of the input rasters will be assigned a NoData value in the output raster (--output). Notice that the Not operator is asymmetrical, and the order of inputs matters.

See Also: And, Or, Xor

Parameters:

Python function:

wbt.Not(
    input1, 
    input2, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Not -v --wd="/path/to/data/" ^
--input1='in1.tif' --input2='in2.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 02/07/2017

Last Modified: 13/10/2018

NotEqualTo

This tool assigns grid cells for which both (--input1 and --input2) input rasters (or one raster and a constant value) have unequal values a new value of 1 (True) in the output raster (--output). All equivalent grid cells are assigned a value of zero (False). Grid cells containing NoData values in either of the inputs will be assigned a NoData value in the output raster.

See Also: EqualTo, GreaterThan, LessThan

Parameters:

Python function:

wbt.not_equal_to(
    input1, 
    input2, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=NotEqualTo -v --wd="/path/to/data/" ^
--input1='in1.tif' --input2='in2.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 01/07/2017

Last Modified: 13/10/2018

Or

This tool is a Boolean OR operator, i.e. it works on True or False (1 and 0) values. Grid cells for which the either the first or second input rasters (--input1; --input2) have a True value are assigned 1 in the output raster, otherwise grid cells are assigned a value of 0. All non-zero values in the input rasters are considered to be True, while all zero-valued grid cells are considered to be False. Grid cells containing NoData values in either of the input rasters will be assigned a NoData value in the output raster (--output).

See Also: And, Not, Xor

Parameters:

Python function:

wbt.Or(
    input1, 
    input2, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Or -v --wd="/path/to/data/" ^
--input1='in1.tif' --input2='in2.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 02/07/2017

Last Modified: 13/10/2018

PairedSampleTTest

This tool will perform a paired-sample t-test to evaluate whether a significant statistical difference exists between the two rasters. The null hypothesis is that the difference between the paired population means is equal to zero. The paired-samples t-test makes an assumption that the differences between related samples follows a Gaussian distribution. The tool will output a cumulative probability distribution, with a fitted Gaussian, to help users evaluate whether this assumption is violated by the data. If this is the case, the WilcoxonSignedRankTest should be used instead.

The user must specify the name of the two input raster images (--input1 and --input2) and the output report HTML file (--output). The test can be performed optionally on the entire image or on a random sub-sample of pixel values of a user-specified size (--num_samples). In evaluating the significance of the test, it is important to keep in mind that given a sufficiently large sample, extremely small and non-notable differences can be found to be statistically significant. Furthermore statistical significance says nothing about the practical significance of a difference.

See Also: TwoSampleKsTest, WilcoxonSignedRankTest

Parameters:

Python function:

wbt.paired_sample_t_test(
    input1, 
    input2, 
    output, 
    num_samples=None, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=PairedSampleTTest -v ^
--wd="/path/to/data/" --input1=input1.tif -input2=input2.tif ^
-o=output.html --num_samples=1000 

Source code on GitHub

Author: Dr. John Lindsay

Created: 24/10/2019

Last Modified: 25/10/2019

PhiCoefficient

Note this tool is part of a WhiteboxTools extension toolset. Please contact Whitebox Geospatial Inc. for information about purchasing a license activation key (https://www.whiteboxgeo.com).

This tool performs a binary classification accuracy assessment, using the Phi coefficient. The Phi coefficient is a measure of association for two binary variables. Introduced by Karl Pearson, this measure is similar to the Pearson correlation coefficient in its interpretation and is related to the chi-squared statistic for a 2×2 contingency table. The user must specify the names of two input images (--input1 and --input2), containing categorical data.

Parameters:

Python function:

wbt.phi_coefficient(
    input1, 
    input2, 
    output, 
    callback=default_callback
)

Command-line Interface:

>> ./whitebox_tools -r=PhiCoefficient --input1=image1.tif ^
--input2=image2.tif' -o=PhiReport.html 

Source code is unavailable due to proprietary license.

Author: Whitebox Geospatial Inc. (c)

Created: 21/04/2021

Last Modified: 21/04/2021

Power

This tool creates a new raster (--output) in which each grid cell is calculated as a value (--input1) raised to the power of another value (--input2). Both inputs can either be rasters or constant values. Moderate to exponent large values will result in very large output values and this may cause errors when you display the data. Grid cells with NoData values in either of the input rasters will be assigned NoData values in the output raster.

See Also: Exp, Exp2

Parameters:

Python function:

wbt.power(
    input1, 
    input2, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Power -v --wd="/path/to/data/" ^
--input1='in1.tif' --input2='in2.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 06/07/2017

Last Modified: 13/10/2018

PrincipalComponentAnalysis

Principal component analysis (PCA) is a common data reduction technique that is used to reduce the dimensionality of multi-dimensional space. In the field of remote sensing, PCA is often used to reduce the number of bands of multi-spectral, or hyper-spectral, imagery. Image correlation analysis often reveals a substantial level of correlation among bands of multi-spectral imagery. This correlation represents data redundancy, i.e. fewer images than the number of bands are required to represent the same information, where the information is related to variation within the imagery. PCA transforms the original data set of n bands into n 'component' images, where each component image is uncorrelated with all other components. The technique works by transforming the axes of the multi-spectral space such that it coincides with the directions of greatest correlation. Each of these new axes are orthogonal to one another, i.e. they are at right angles. PCA is therefore a type of coordinate system transformation. The PCA component images are arranged such that the greatest amount of variance (or information) within the original data set, is contained within the first component and the amount of variance decreases with each component. It is often the case that the majority of the information contained in a multi-spectral data set can be represented by the first three or four PCA components. The higher-order components are often associated with noise in the original data set.

The user must specify the names of the multiple input images (--inputs). Additionally, the user must specify whether to perform a standardized PCA (--standardized) and the number of output components (--num_comp) to generate (all components will be output unless otherwise specified). A standardized PCA is performed using the correlation matrix rather than the variance-covariance matrix. This is appropriate when the variances in the input images differ substantially, such as would be the case if they contained values that were recorded in different units (e.g. feet and meters) or on different scales (e.g. 8-bit vs. 16 bit).

Several outputs will be generated when the tool has completed. The PCA report will be embeded within an output (--output) HTML file, which should be automatically displayed after the tool has completed. This report contains useful data summarizing the results of the PCA, including the explained variances of each factor, the Eigenvalues and Eigenvectors associated with factors, the factor loadings, and a scree plot. The first table that is in the PCA report lists the amount of explained variance (in non-cumulative and cumulative form), the Eigenvalue, and the Eigenvector for each component. Each of the PCA components refer to the newly created, transformed images that are created by running the tool. The amount of explained variance associated with each component can be thought of as a measure of how much information content within the original multi-spectral data set that a component has. The higher this value is, the more important the component is. This same information is presented in graphical form in the scree plot, found at the bottom of the PCA report. The Eigenvalue is another measure of the information content of a component and the eigenvector describes the mathematical transformation (rotation coordinates) that correspond to a particular component image.

Factor loadings are also output in a table within the PCA text report (second table). These loading values describe the correlation (i.e. r values) between each of the PCA components (columns) and the original images (rows). These values show you how the information contained in an image is spread among the components. An analysis of factor loadings can be reveal useful information about the data set. For example, it can help to identify groups of similar images.

PCA is used to reduce the number of band images necessary for classification (i.e. as a data reduction technique), for noise reduction, and for change detection applications. When used as a change detection technique, the major PCA components tend to be associated with stable elements of the data set while variance due to land-cover change tend to manifest in the high-order, 'change components'. When used as a noise reduction technique, an inverse PCA is generally performed, leaving out one or more of the high-order PCA components, which account for noise variance.

Note: the current implementation reads every raster into memory at one time. This is because of the calculation of the co-variances. As such, if the entire image stack cannot fit in memory, the tool will likely experience an out-of-memory error. This tool should be run using the --wd flag to specify the working directory into which the component images will be written.

Parameters:

Python function:

wbt.principal_component_analysis(
    inputs, 
    output, 
    num_comp=None, 
    standardized=False, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=PrincipalComponentAnalysis -v ^
--wd='/path/to/data/' -i='image1.tif;image2.tif;image3.tif' ^
--output=report.html --num_comp=3 --standardized 

Source code on GitHub

Author: Dr. John Lindsay

Created: 15/03/2018

Last Modified: 18/10/2019

Quantiles

This tool transforms values in an input raster (--input) into quantiles. In statistics, quantiles are cut points dividing the range of a probability distribution into continuous intervals with equal probabilities, or dividing the observations in a sample in a same way. There is one fewer quantile than the number of groups created. Thus quartiles are the three cut points that will divide a dataset into four equal-sized groups. Common quantiles have special names: for instance quartile (4-quantile), quintiles (5-quantiles), decile (10-quantile), percentile (100-quantile).

The user must specify the desired number of quantiles, q (--num_quantiles), in the output raster (--output). The output raster will contain q equal-sized groups with values 1 to q, indicating which quantile group each grid cell belongs to.

See Also: HistogramEqualization

Parameters:

Python function:

wbt.quantiles(
    i, 
    output, 
    num_quantiles=5, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Quantiles -v --wd="/path/to/data/" ^
-i=DEM.tif -o=output.tif --num_quantiles=5 

Source code on GitHub

Author: Dr. John Lindsay

Created: 01/07/2017

Last Modified: 13/10/2018

RandomField

This tool can be used to a raster image filled with random values drawn from a standard normal distribution. The values range from appoximately -4.0 to 4.0, with a mean of 0 and a standard deviation of 1.0. The dimensions and georeferencing of the output random field (--output) are based on an existing, user-specified raster grid (--base). Note that the output field will not possess any spatial autocorrelation. If spatially autocorrelated random fields are desired, the TurningBandsSimulation tool is more appropriate, or alternatively, the FastAlmostGaussianFilter tool may be used to force spatial autocorrelation onto the distribution of the RandomField tool.

See Also: TurningBandsSimulation, FastAlmostGaussianFilter

Parameters:

Python function:

wbt.random_field(
    base, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=RandomField -v --wd="/path/to/data/" ^
--base=in.tif -o=out.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 11/07/2017

Last Modified: 13/10/2018

RandomSample

This tool can be used to create a random sample of grid cells. The user specifies the base raster file, which is used to determine the grid dimensions and georeference information for the output raster, and the number of sample random samples (n). The output grid will contain n non-zero grid cells, randomly distributed throughout the raster grid, and a background value of zero. This tool is useful when performing statistical analyses on raster images when you wish to obtain a random sample of data.

Only valid, non-nodata, cells in the base raster will be sampled.

Parameters:

Python function:

wbt.random_sample(
    base, 
    output, 
    num_samples=1000, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=RandomSample -v --wd="/path/to/data/" ^
--base=in.tif -o=out.tif --num_samples=1000 

Source code on GitHub

Author: Dr. John Lindsay

Created: January 2, 2018

Last Modified: 13/10/2018

RasterHistogram

This tool produces a histogram (i.e. a frequency distribution graph) for the values contained within an input raster file (--input). The histogram will be embeded within an output (--output) HTML file, which should be automatically displayed after the tool has completed.

See Also: AttributeHistogram

Parameters:

Python function:

wbt.raster_histogram(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=RasterHistogram -v ^
--wd="/path/to/data/" -i="file1.tif" -o=outfile.html 

Source code on GitHub

Author: Dr. John Lindsay

Created: 19/12/2017

Last Modified: 24/01/2019

RasterSummaryStats

This tool outputs distribution summary statistics for input raster images (--input). The distribution statistics include the raster minimum, maximum, range, total, mean, variance, and standard deviation. These summary statistics are output to the system stdout.

The following is an example of the summary report:

*********************************
* Welcome to RasterSummaryStats *
*********************************
Reading data...

Number of non-nodata grid cells: 32083559
Number of nodata grid cells: 3916441
Image minimum: 390.266357421875
Image maximum: 426.0322570800781
Image range: 35.765899658203125
Image total: 13030334843.332886
Image average: 406.13745012929786
Image variance: 31.370027239143383
Image standard deviation: 5.600895217654351

See Also: RasterHistogram, ZonalStatistics

Parameters:

Python function:

wbt.raster_summary_stats(
    i, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=RasterSummaryStats -v ^
--wd="/path/to/data/" -i=DEM.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 01/07/2017

Last Modified: 13/10/2018

Reciprocal

This tool creates a new raster (--output) in which each grid cell is equal to one divided by the grid cell values in the input raster image (--input). NoData values in the input image will be assigned NoData values in the output image.

Parameters:

Python function:

wbt.reciprocal(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Reciprocal -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 06/07/2017

Last Modified: 13/10/2018

RescaleValueRange

Performs a min-max contrast stretch on an input greytone image.

Parameters:

Python function:

wbt.rescale_value_range(
    i, 
    output, 
    out_min_val, 
    out_max_val, 
    clip_min=None, 
    clip_max=None, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=RescaleValueRange -v ^
--wd="/path/to/data/" -i=input.tif -o=output.tif ^
--out_min_val=0.0 --out_max_val=1.0
>>./whitebox_tools ^
-r=RescaleValueRange -v --wd="/path/to/data/" -i=input.tif ^
-o=output.tif --out_min_val=0.0 --out_max_val=1.0 ^
--clip_min=45.0 --clip_max=200.0 

Source code on GitHub

Author: Dr. John Lindsay

Created: September 10, 2017

Last Modified: 30/01/2020

RootMeanSquareError

This tool calculates the root-mean-square-error (RMSE) or root-mean-square-difference (RMSD) from two input rasters. If the two input rasters possess the same number of rows and columns, the RMSE is calucated on a cell-by-cell basis, otherwise bilinear resampling is used. In addition to RMSE, the tool also reports other common accuracy statistics including the mean verical error, the 95% confidence limit (RMSE x 1.96), and the 90% linear error (LE90), which is the 90% percentile of the residuals between two raster surfaces. The LE90 is the most robust of the reported accuracy statistics when the residuals are non-Gaussian. The LE90 requires sorting the residual values, which can be a relatively slow operation for larger rasters.

See Also: PairedSampleTTest, WilcoxonSignedRankTest

Parameters:

Python function:

wbt.root_mean_square_error(
    i, 
    base, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=RootMeanSquareError -v ^
--wd="/path/to/data/" -i=DEM.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: September 18, 2017

Last Modified: 13/10/2018

Round

This tool rounds the values in an input raster (--input) to the nearest integer value. Half-way cases are rounded away from zero (e.g. round(0.5) = 1, round(-4.5) = -5). The output raster (--output) will be of an I32 data type.

See Also: Ceil, Floor, Truncate

Parameters:

Python function:

wbt.round(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Round -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 06/07/2017

Last Modified: 26/10/2019

Sin

This tool creates a new raster (--output) in which each grid cell is equal to the sine (sin) of the corresponding grid cell in an input raster (--input). The input raster image should contain angular data measured in radians. You may convert a raster containing degrees to radians using the ToRadians tool. Grid cells with NoData values in the input raster will be assigned NoData values in the output raster.

See Also: Cos, Tan, ArcSin, ToRadians

Parameters:

Python function:

wbt.sin(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Sin -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 05/07/2017

Last Modified: 13/10/2018

Sinh

This tool creates a new raster (--output) in which each grid cell is equal to the hyperbolic sine (sinh) of the corresponding grid cell in an input raster (--input). The input raster image should contain angular data measured in radians. You may convert a raster containing degrees to radians using the ToRadians tool. Grid cells with NoData values in the input raster will be assigned NoData values in the output raster.

See Also: Cosh, Tanh, ToRadians

Parameters:

Python function:

wbt.sinh(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Sinh -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 06/07/2017

Last Modified: 13/10/2018

Square

This tool creates a new raster (--output) in which each grid cell is equal to the square of the value of the corresponding grid cell in the input raster (--input), i.e. the input raster is raised to the power of two. NoData values in the input image will be assigned NoData values in the output image.

See Also: SquareRoot

Parameters:

Python function:

wbt.square(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Square -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 06/07/2017

Last Modified: 13/10/2018

SquareRoot

This tool creates a new raster (--output) in which each grid cell is equal to the square root of the value of the corresponding grid cell in the input raster (--input). NoData values in the input image will be assigned NoData values in the output image.

See Also: Square

Parameters:

Python function:

wbt.square_root(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=SquareRoot -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 06/07/2017

Last Modified: 26/10/2019

Subtract

This tool creates a new raster in which each grid cell is equal to the subtraction (difference) of the corresponding grid cells in two input rasters or one input raster and a constant value. If two images are input, both images must possess the same number of rows and columns and spatial extent, as the analysis will be carried out on a cell-by-cell basis. If a grid cell contains a NoData value in either of the input images, the cell will be excluded from the analysis.

See Also: Add, Divide, Multiply, InPlaceSubtract

Parameters:

Python function:

wbt.subtract(
    input1, 
    input2, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Subtract -v --wd="/path/to/data/" ^
--input1='in1.tif' --input2='in2.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 05/07/2017

Last Modified: 24/01/2019

Tan

This tool creates a new raster (--output) in which each grid cell is equal to the tangent (tan) of the corresponding grid cell in an input raster (--input). The input raster image should contain angular data measured in radians. You may convert a raster containing degrees to radians using the ToRadians tool. Grid cells with NoData values in the input raster will be assigned NoData values in the output raster.

See Also: Cos, Sin, ArcTan, ToRadians

Parameters:

Python function:

wbt.tan(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Tan -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 05/07/2017

Last Modified: 13/10/2018

Tanh

This tool creates a new raster (--output) in which each grid cell is equal to the hyperbolic tangent (tanh) of the corresponding grid cell in an input raster (--input). The input raster image should contain angular data measured in radians. You may convert a raster containing degrees to radians using the ToRadians tool. Grid cells with NoData values in the input raster will be assigned NoData values in the output raster.

See Also: Cosh, Sinh, ToRadians

Parameters:

Python function:

wbt.tanh(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Tanh -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 06/07/2017

Last Modified: 13/10/2018

ToDegrees

This tool converts the radians values contained within an input raster (--input) to degrees in the output raster (--output). One degree is approximately 0.017453293 (π / 180) radians. Conversion between degrees and radians is common when working with trigonometric functions.

See Also: ToRadians

Parameters:

Python function:

wbt.to_degrees(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=ToDegrees -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 06/07/2017

Last Modified: 13/10/2018

ToRadians

This tool converts the degree values contained within an input raster (--input) to radians in the output raster (--output). One radian is just under 57.3 (180 / π) degrees. Conversion between degrees and radians is common when working with trigonometric functions.

See Also: ToDegrees

Parameters:

Python function:

wbt.to_radians(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=ToRadians -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 06/07/2017

Last Modified: 13/10/2018

TrendSurface

This tool can be used to interpolate a trend surface from a raster image. The technique uses a polynomial, least-squares regression analysis. The user must specify the name of the input raster file. In addition, the user must specify the polynomial order (1 to 10) for the analysis. A first-order polynomial is a planar surface with no curvature. As the polynomial order is increased, greater flexibility is allowed in the fitted surface. Although polynomial orders as high as 10 are accepted, numerical instability in the analysis often creates artifacts in trend surfaces of orders greater than 5. The operation will display a text report on completion, in addition to the output raster image. The report will list each of the coefficient values and the r-square value. Note that the entire raster image must be able to fit into computer memory, limiting the use of this tool to relatively small rasters. The Trend Surface (Vector Points) tool can be used instead if the input data is vector points contained in a shapefile.

Numerical stability is enhanced by transforming the x, y, z data by their minimum values before performing the regression analysis. These transform parameters are also reported in the output report.

Parameters:

Python function:

wbt.trend_surface(
    i, 
    output, 
    order=1, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=TrendSurface -v --wd="/path/to/data/" ^
-i='input.tif' -o='output.tif' --order=2 

Source code on GitHub

Author: Dr. John Lindsay

Created: 30/04/2018

Last Modified: 13/10/2018

TrendSurfaceVectorPoints

This tool can be used to interpolate a trend surface from a vector points file. The technique uses a polynomial, least-squares regression analysis. The user must specify the name of the input shapefile, which must be of a 'Points' base ShapeType and select the attribute in the shapefile's associated attribute table for which to base the trend surface analysis. The attribute must be numerical. In addition, the user must specify the polynomial order (1 to 10) for the analysis. A first-order polynomial is a planar surface with no curvature. As the polynomial order is increased, greater flexibility is allowed in the fitted surface. Although polynomial orders as high as 10 are accepted, numerical instability in the analysis often creates artifacts in trend surfaces of orders greater than 5. The operation will display a text report on completion, in addition to the output raster image. The report will list each of the coefficient values and the r-square value. The Trend Surface tool can be used instead if the input data is a raster image.

Numerical stability is enhanced by transforming the x, y, z data by their minimum values before performing the regression analysis. These transform parameters are also reported in the output report.

Parameters:

Python function:

wbt.trend_surface_vector_points(
    i, 
    field, 
    output, 
    cell_size, 
    order=1, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=TrendSurfaceVectorPoints -v ^
--wd="/path/to/data/" -i='input.shp' --field=ELEV ^
-o='output.tif' --order=2 --cell_size=10.0 

Source code on GitHub

Author: Dr. John Lindsay

Created: 01/05/2018

Last Modified: 13/10/2018

Truncate

This tool truncates the values in an input raster (--input); truncation limits the number of digits right of the decimal point. For example, trunc(3.2) = 3 and trunc(5.8) = 5 The output raster (--output) will be of an I32 data type.

See Also: Round, Ceil, Floor

Parameters:

Python function:

wbt.truncate(
    i, 
    output, 
    num_decimals=None, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Truncate -v --wd="/path/to/data/" ^
-i='input.tif' -o=output.tif --num_decimals=2 

Source code on GitHub

Author: Dr. John Lindsay

Created: 06/07/2017

Last Modified: 30/01/2020

TurningBandsSimulation

This tool can be used to create a random field using the turning bands algorithm. The user must specify the name of a base raster image (--base) from which the output raster will derive its geographical information, dimensions (rows and columns), and other information. In addition, the range (--range), in x-y units, must be specified. The range determines the correlation length of the resulting field. For a good description of how the algorithm works, see Carr (2002). The turning bands method creates a number of 1-D simulations (called bands) and fuses these together to create a 2-D error field. There is no natural stopping condition in this process, so the user must specify the number of bands to create (--iterations). The default value of 1000 iterations is reasonable. The fewer iterations used, the more prevalent the 1-D simulations will be in the output error image, effectively creating artifacts. Run time increases with the number of iterations.

Turning bands simulation is a commonly applied technique in Monte Carlo style simulations of uncertainty. As such, it is frequently run many times during a simulation (often 1000s of times). When this is the case, algorithm performance and efficiency are key considerations. One alternative method to efficiently generate spatially autcorrelated random fields is to apply the FastAlmostGaussianFilter tool to the output of the RandomField tool. This can be used to generate a random field with the desired spatial characteristics and frequency distribution. This is the alternative approach used by the StochasticDepressionAnalysis tool.

Reference:

Carr, J. R. (2002). Data visualization in the geosciences. Upper Saddle River, NJ: Prentice Hall. pp. 267.

See Also: RandomField, FastAlmostGaussianFilter, StochasticDepressionAnalysis

Parameters:

Python function:

wbt.turning_bands_simulation(
    base, 
    output, 
    range, 
    iterations=1000, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=TurningBandsSimulation -v ^
--wd="/path/to/data/" --base=in.tif -o=out.tif --range=850.0 ^
--iterations=2500 

Source code on GitHub

Author: Dr. John Lindsay

Created: 14/07/2017

Last Modified: 30/01/2020

TwoSampleKsTest

This tool will perform a two-sample Kolmogorov-Smirnov (K-S) test to evaluate whether a significant statistical difference exists between the frequency distributions of two rasters. The null hypothesis is that both samples come from a population with the same distribution. Note that this test evaluates the two input rasters for differences in their overall distribution shape, with no assumption of normality. If there is need to compare the per-pixel differences between two input rasters, a paired-samples test such as the PairedSampleTTest or the non-parametric WilcoxonSignedRankTest should be used instead.

The user must specify the name of the two input raster images (--input1 and --input2) and the output report HTML file (--output). The test can be performed optionally on the entire image or on a random sub-sample of pixel values of a user-specified size (--num_samples). In evaluating the significance of the test, it is important to keep in mind that given a sufficiently large sample, extremely small and non-notable differences can be found to be statistically significant. Furthermore statistical significance says nothing about the practical significance of a difference.

See Also: KSTestForNormality, PairedSampleTTest, WilcoxonSignedRankTest

Parameters:

Python function:

wbt.two_sample_ks_test(
    input1, 
    input2, 
    output, 
    num_samples=None, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=TwoSampleKsTest -v ^
--wd="/path/to/data/" --input1=input1.tif -input2=input2.tif ^
-o=output.html --num_samples=1000 

Source code on GitHub

Author: Dr. John Lindsay

Created: 21/10/2019

Last Modified: 24/10/2019

WilcoxonSignedRankTest

This tool will perform a Wilcoxon signed-rank test to evaluate whether a significant statistical difference exists between the two rasters. The Wilcoxon signed-rank test is often used as a non-parametric equivalent to the paired-samples Student's t-test, and is used when the distribution of sample difference values between the paired inputs is non-Gaussian. The null hypothesis of this test is that difference between the sample pairs follow a symmetric distribution around zero. i.e. that the median difference between pairs of observations is zero.

The user must specify the name of the two input raster images (--input1 and --input2) and the output report HTML file (--output). The test can be performed optionally on the entire image or on a random sub-sample of pixel values of a user-specified size (--num_samples). In evaluating the significance of the test, it is important to keep in mind that given a sufficiently large sample, extremely small and non-notable differences can be found to be statistically significant. Furthermore statistical significance says nothing about the practical significance of a difference. Note that cells with a difference of zero are excluded from the ranking and tied difference values are assigned their average rank values.

See Also: PairedSampleTTest, TwoSampleKsTest

Parameters:

Python function:

wbt.wilcoxon_signed_rank_test(
    input1, 
    input2, 
    output, 
    num_samples=None, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=WilcoxonSignedRankTest -v ^
--wd="/path/to/data/" --input1=input1.tif -input2=input2.tif ^
-o=output.html --num_samples=1000 

Source code on GitHub

Author: Dr. John Lindsay

Created: 25/10/2019

Last Modified: 25/10/2019

Xor

This tool is a Boolean XOR operator, i.e. it works on True or False (1 and 0) values. Grid cells for which either the first or second input rasters (--input1; --input2) have a True value but not both are assigned 1 in the output raster, otherwise grid cells are assigned a value of 0. All non-zero values in the input rasters are considered to be True, while all zero-valued grid cells are considered to be False. Grid cells containing NoData values in either of the input rasters will be assigned a NoData value in the output raster (--output). Notice that the Not operator is asymmetrical, and the order of inputs matters.

See Also: Or, And, Not

Parameters:

Python function:

wbt.xor(
    input1, 
    input2, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=Xor -v --wd="/path/to/data/" ^
--input1='in1.tif' --input2='in2.tif' -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 02/07/2017

Last Modified: 13/10/2018

ZScores

This tool will transform the values in an input raster image (--input) into z-scores. Z-scores are also called standard scores, normal scores, or z-values. A z-score is a dimensionless quantity that is calculated by subtracting the mean from an individual raw value and then dividing the difference by the standard deviation. This conversion process is called standardizing or normalizing and the result is sometimes referred to as a standardized variable. The mean and standard deviation are estimated using all values in the input image except for NoData values. The input image should not have a Boolean or categorical data scale, i.e. it should be on a continuous scale.

See Also: CumulativeDistribution

Parameters:

Python function:

wbt.z_scores(
    i, 
    output, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=ZScores -v --wd="/path/to/data/" ^
-i=DEM.tif -o=output.tif 

Source code on GitHub

Author: Dr. John Lindsay

Created: 01/07/2017

Last Modified: 13/10/2018

ZonalStatistics

This tool can be used to extract common descriptive statistics associated with the distribution of some underlying data raster based on feature units defined by a feature definition raster. For example, this tool can be used to measure the maximum or average slope gradient (data image) for each of a group of watersheds (feature definitions). Although the data raster can contain any type of data, the feature definition raster must be categorical, i.e. it must define area entities using integer values.

The --stat parameter can take the values, 'mean', 'median', 'minimum', 'maximum', 'range', 'standard deviation', or 'total'.

If an output image name is specified, the tool will assign the descriptive statistic value to each of the spatial entities defined in the feature definition raster. If text output is selected, an HTML table will be output, which can then be readily copied into a spreadsheet program for further analysis. This is a very powerful and useful tool for creating numerical summary data from spatial data which can then be interrogated using statistical analyses. At least one output type (image or text) must be specified for the tool to operate.

NoData values in either of the two input images are ignored during the calculation of the descriptive statistic.

See Also: RasterSummaryStats

Parameters:

Python function:

wbt.zonal_statistics(
    i, 
    features, 
    output=None, 
    stat="mean", 
    out_table=None, 
    callback=default_callback
)

Command-line Interface:

>>./whitebox_tools -r=ZonalStatistics -v ^
--wd="/path/to/data/" -i='input.tif' --features='groups.tif' ^
-o='output.tif' --stat='minimum'
>>./whitebox_tools ^
-r=ZonalStatistics -v --wd="/path/to/data/" -i='input.tif' ^
--features='groups.tif' --out_table='output.html' 

Source code on GitHub

Author: Dr. John Lindsay

Created: Dec. 15, 2017

Last Modified: 17/07/2019