Ln function

Available with Image Analyst license.

Available with Spatial Analyst license.

Overview

Calculates the natural logarithm (base e) of each pixel in a raster.

Notes

The natural logarithm (Ln) is the most commonly used logarithmic function.

The input Raster can be an integer or a floating point. The output of this tool is always a floating point, regardless of the input type.

Input values that are 0 or negative will be NoData in the output raster.

If the input is a multiband raster, the output will be a multiband raster. The function will perform the operation on each band in the input.

If the input is a multidimensional raster, all slices from all variables will be processed, and the output will be a multidimensional raster.

Parameters

Parameter name	Description
Raster	Input values for which to find the natural logarithm (Ln).
Extent Type	Choose which extent should be used in the output raster: First Of—Use the extent of the first input raster to determine the processing extent. Intersection Of—Use the extent of the overlapping pixels to determine the processing extent. This is the default. Union Of—Use the extent of all the rasters to determine the processing extent. Last Of—Use the extent of the last input raster to determine the processing extent.
Cellsize Type	Choose which cell size to use in the output raster. If all the input cell sizes are the same, all the options will yield the same results. First Of—Use the first cell size of the input rasters. Min Of—Use the smallest cell size of all the input rasters. Max Of—Use the largest cell size of all the input rasters. This is the default. Mean Of—Use the mean cell size of all the input rasters. Last Of—Use the last cell size of the input rasters.