ATan function

Available with Image Analyst license.

Available with Spatial Analyst license.

Overview

Calculates the inverse tangent of the pixels in a raster.

Notes

In mathematics, all trigonometric functions have a defined range of valid input values, called the domain. The output values from each function also have a defined range. For this tool, the domain and range are as follows:

• Domain: -∞ < [in_value] < ∞
• Range: -pi/2 ≤ [out_value] ≤ pi/2

Note that -∞ and ∞ represent the smallest negative and largest positive value supported by the particular raster format, respectively.

The input values to this tool are in radians. If degrees are desired, the resulting raster must be multiplied by the radians-to-degrees conversion factor of 180/pi, or approximately 57.296.

The output raster is always a floating-point type, regardless of the input value type.

The output values from this tool are interpreted as unitless.

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	The input for which to calculate the inverse tangent values.
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.