ATan2 (Spatial Analyst)

Summary

Calculates the inverse tangent (based on x,y) of cells in a raster.

Illustration

ATan2 illustration
OutRas = ATan2(InRas1, InRas2)

Usage

Syntax

ATan2 (in_raster_or_constant1, in_raster_or_constant2)
ParameterExplanationData Type
in_raster_or_constant1

The input that specifies the numerator, or y value, to use when calculating the inverse tangent.

A number can be used as an input for this parameter, provided a raster is specified for the other parameter. To be able to specify a number for both inputs, the cell size and extent must first be set in the environment.

Raster Layer | Constant
in_raster_or_constant2

The input that specifies the denominator, or x value, to use when calculating the inverse tangent.

A number can be used as an input for this parameter, provided a raster is specified for the other parameter. To be able to specify a number for both inputs, the cell size and extent must first be set in the environment.

Raster Layer | Constant

Return Value

NameExplanationData Type
out_raster

The output raster.

The values are the inverse tangent angle of the input values.

Raster

Code Sample

ATan2 example 1 (Python window)

This example calculates the inverse tangent for two input GRID rasters.

import arcpy
from arcpy import env
from arcpy.sa import *
env.workspace = "C:/sapyexamples/data"
outATan2 = ATan2("degs", "negs")
outATan2.save("C:/sapyexamples/output/outatan2")
ATan2 example 2 (stand-alone script)

This example calculates the inverse tangent for two input GRID rasters.

# Name: ATan2_Ex_02.py
# Description: Calculates the inverse tangent of cells based
#              on (y, x) values from two rasters
# Requirements: Spatial Analyst Extension
# Author: ESRI

# Import system modules
import arcpy
from arcpy import env
from arcpy.sa import *

# Set environment settings
env.workspace = "C:/sapyexamples/data"

# Set local variables
inRaster1 = "degs"
inRaster2 = "negs"

# Check out the ArcGIS Spatial Analyst extension license
arcpy.CheckOutExtension("Spatial")

# Execute ATan2
outATan2 = ATan2(inRaster1, inRaster2)

# Save the output 
outATan2.save("C:/sapyexamples/output/outatan2.tif")

Environments

Related Topics

Licensing Information

ArcView: Requires Spatial Analyst
ArcEditor: Requires Spatial Analyst
ArcInfo: Requires Spatial Analyst

6/29/2011