Available with Spatial Analyst license.
To use degrees as inputs for trigonometric tools, the values need to be converted into radians. To do the conversion, multiply the input values by pi/180, or approximately 0.01745.
In Python, this conversion can be done directly in the expression, or you can define a variable to store the value once and reuse it as needed. Using the Cos tool as an example, the syntax could be in the following form:
>>> import math
>>> from arcpy.sa import *
>>> OutRas = Cos (InRas * math.pi / 180.0)
Or, you can use a variable for the conversion factor:
>>> import math
>>> deg2rad = math.pi / 180.0
>>> from arcpy.sa import *
>>> OutRas = Cos (InRas * deg2rad)
The following illustrations demonstrate converting inputs whose values are in degrees into radians before performing the particular operation.
Examples of converting trigonometric inputs to radians
Tool | Illustration and Python syntax |
Cos | |
Sin | |
Tan |