ASin (Spatial Analyst)

Available with Spatial Analyst license.

Available with Image Analyst license.

Summary

Calculates the inverse sine of cells in a raster.

Illustration

ASin illustration
OutRas = ASin(InRas)

Usage

  • 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 following are true:

    • The Domain is: -1 ≤ [in_value] ≤ 1

      Note that any input value that is outside this domain will receive NoData on the output raster.

    • The Range is: -pi/2 ≤ [out_value] ≤ pi/2

  • The input values to this tool are interpreted as unitless.

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

  • The output values from this tool are in radians. To use degrees instead, the resulting raster must be multiplied 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 output in radians to degrees are available.

  • 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.

  • In ArcPy, if the input is a multidimensional raster, all slices from all variables will be processed, and the output will be a multidimensional raster.

  • See Analysis environments and Spatial Analyst for additional details on the geoprocessing environments that apply to this tool.

Parameters

LabelExplanationData Type
Input raster or constant value

The input for which to calculate the inverse sine 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

LabelExplanationData Type
Output raster

The output raster.

The values are the inverse sine of the input values.

Raster

ASin(in_raster_or_constant)
NameExplanationData Type
in_raster_or_constant

The input for which to calculate the inverse sine 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
out_raster

The output raster.

The values are the inverse sine of the input values.

Raster

Code sample

ASin example 1 (Python window)

This example calculates the inverse sine of the values in the input Grid raster.

import arcpy
from arcpy import env
from arcpy.sa import *
env.workspace = "C:/sapyexamples/data"
outASin = ASin("degs")
outASin.save("C:/sapyexamples/output/outasin")
ASin example 2 (stand-alone script)

This example calculates the inverse sine of the values in the input Grid raster and outputs an IMG raster.

# Name: ASin_Ex_02.py
# Description: Calculates the inverse sine of cells in a raster
# Requirements: Spatial Analyst Extension

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

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

# Set local variables
inRaster = "degs"

# Execute ASin
outASin = ASin(inRaster)

# Save the output 
outASin.save("C:/sapyexamples/output/outasin.img")

Licensing information

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

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