An overview of transformation classes

Available with Spatial Analyst license.

The Transformation Function classes are used to define the particular transformation function to apply to the input raster values. There are thirteen transformation function classes, each of which defines a specific function. When a transformation function object is defined, that function will be applied to each cell in the raster and the resulting function values will be linearly transformed to the specified evaluation scale. The transformation function object is an optional parameter in the Rescale by Function tool.

If you do not define a transformation function object, then the default MSSmall transformation function is used.

TfExponential	Defines an Exponential transformation function which is determined from the shift and base factor shape–controlling parameters as well as the lower and upper threshold that identify the range within which to apply the function.
TfGaussian	Defines a Gaussian transformation function which is determined from the midpoint and spread shape–controlling parameters as well as the lower and upper threshold that identify the range within which to apply the function.
TfLarge	Defines a Large transformation function which is determined from the midpoint and spread shape–controlling parameters as well as the lower and upper threshold that identify the range within which to apply the function.
TfLinear	Defines a Linear transformation function which is determined from the minimum and maximum shape–controlling parameters as well as the lower and upper threshold that identify the range within which to apply the function.
TfLogarithm	Defines a Logarithm transformation function which is determined from the shift and factor shape–controlling parameters as well as the lower and upper threshold that identify the range within which to apply the function.
TfLogisticDecay	Defines a Logistic Decay transformation function which is determined from the minimum, maximum, and y intercept percent shape–controlling parameters as well as the lower and upper threshold that identify the range within which to apply the function.
TfLogisticGrowth	Defines a Logistic Growth transformation function which is determined from the minimum, maximum, and y intercept percent shape–controlling parameters as well as the lower and upper threshold that identify the range within which to apply the function.
TfMSLarge	Defines an MSLarge transformation function which is determined from the mean multiplier and standard deviation multiplier shape–controlling parameters as well as the lower and upper threshold that identify the range within which to apply the function.
TfMSSmall	Defines an MSSmall transformation function which is determined from the mean multiplier and standard deviation multiplier shape–controlling parameters as well as the lower and upper threshold that identify the range within which to apply the function.
TfNear	Defines a Near transformation function which is determined from the midpoint and spread shape–controlling parameters as well as the lower and upper threshold that identify the range within which to apply the function.
TfPower	Defines a Power transformation function which is determined from the shift and exponent shape–controlling parameters as well as the lower and upper threshold that identify the range within which to apply the function.
TfSmall	Defines a Small transformation function which is determined from the midpoint and spread shape–controlling parameters as well as the lower and upper threshold that identify the range within which to apply the function.
TfSymmetricLinear	Defines a Symmetric Linear transformation function which is determined from the minimum and maximum shape–controlling parameters as well as the lower and upper threshold that identify the range within which to apply the function.

Tools that use the transformation objects

• Rescale by Function

Once several input rasters have been transformed, the rasters can be used in various applications, the most common being for suitability modeling.