Tan (Image Analyst)

Available with Spatial Analyst license.

Available with Image Analyst license.


Calculates the tangent of cells in a raster.


Tan illustration
OutRas = Tan(InRas)


  • In mathematics, all trigonometric functions have a defined range of valid input values, called the domain. The output values from each function also has a defined range. For this tool

    • The Domain is : -∞ < [in_value] < ∞

    • The Range is : -∞ < [out_value] < ∞

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

  • The input values for this tool are interpreted to be in radians. If the input you want to use is in degrees, the values must first be divided by the radians-to-degrees conversion factor of 180/pi, or approximately 57.296.

    For further assistance, a procedure to follow and examples of converting input values in degrees to radians are available.

  • The output values from this tool are interpreted as unitless.

  • Output values are always floating point, regardless of the input data type.

  • Due to the range of values, applying a Histogram Equalized stretch renderer can be useful to best see the results.

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


ParameterExplanationData Type

The input for which to calculate the tangent values.

To use a number as an input for this parameter, the cell size and extent must first be set in the environment.

Raster Layer; Constant

Return Value

NameExplanationData Type

The output raster.

The values are the tangent of the input values.


Code sample

Tan example 1 (Python window)

This example calculates the tangent of the values in the input Grid raster.

import arcpy
from arcpy import env
from arcpy.ia import *
env.workspace = "C:/iapyexamples/data"
outTan = Tan("degs")
Tan example 2 (stand-alone script)

This example calculates the tangent of the values in the input Grid raster and outputs a TIFF raster.

# Name: Tan_Ex_02.py
# Description: Calculates the tangent of pixels in a raster
# Requirements: Image Analyst Extension

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

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

# Set local variables
inRaster = "degs"

# Check out the ArcGIS Image Analyst extension license

# Execute Tan
outTan = Tan(inRaster)

# Save the output 

Licensing information

  • Basic: Requires Image Analyst or Spatial Analyst
  • Standard: Requires Image Analyst or Spatial Analyst
  • Advanced: Requires Image Analyst or Spatial Analyst

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