# Cos (Spatial Analyst)

## Summary

Calculates the cosine of cells in a raster.

## Illustration

 OutRas = Cos(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 Domain is : -∞ < [in_value] < ∞

• The Range is : -1 ≤ [out_value] ≤ 1

Note that here -∞ 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 wish 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.

See here for examples of converting input values that are in degrees to the expected units of radians.

• The output values from Cos are interpreted as unitless.

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

• Due to the range of values, applying a linear stretch renderer can be useful to better see the results.

## Syntax

Cos (in_raster_or_constant)
 Parameter Explanation Data Type in_raster_or_constant The input for which to calculate the cosine values. In order 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

 Name Explanation Data Type out_raster The output raster. The values are the cosine of the input values. Raster

## Code Sample

Cos example 1 (Python window)

This example calculates the cosine of the values in the input GRID raster.

```import arcpy
from arcpy import env
from arcpy.sa import *
env.workspace = "C:/sapyexamples/data"
outCos = Cos("degs")
outCos.save("C:/sapyexamples/output/outcos")```
Cos example 2 (stand-alone script)

This example calculates the cosine of the values in the input GRID raster and outputs a TIFF raster.

```# Name: Cos_Ex_02.py
# Description: Calculates the cosine of cells in a raster
# 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
inRaster = "degs"

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

# Execute Cos
outCos = Cos(inRaster)

# Save the output
outCos.save("C:/sapyexamples/output/outcos.tif")```

## Licensing Information

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

6/29/2011