# Exp

## Summary

Calculates the base e exponential of the cells in a raster.

## Usage

• Input values can be integer or float, and can be negative as well as positive.

You can review some results for both positive and negative floating-point input values in the examples of output values from the Exponential tools.

• The base e exponential is the most commonly used exponential function.

• Input values less than or equal to -745 will be set to NoData in the output, because these values cannot be accurately represented by 32-bit floating-point numbers.

• The output raster from this tool is always floating-point type, regardless of the input value type.

• Output values from this tool are always positive.

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

## Syntax

`Exp (in_raster_or_constant)`
 Parameter Explanation Data Type in_raster_or_constant The input values for which to find the base e exponential.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 cell values are the base e exponential of the input values. Raster

## Code sample

Exp example 1 (Python window)

This example calculates the base e exponential of the input raster values, and returns the result as a TIFF raster.

``````import arcpy
from arcpy import env
from arcpy.sa import *
env.workspace = "C:/sapyexamples/data"
outExp = Exp("landuse")
outExp.save("C:/sapyexamples/output/outexp.tif")``````
Exp example 2 (stand-alone script)

This example calculates the base e exponential of the input raster values.

``````# Name: Exp_Ex_02.py
# Description: Calculates the base e exponential 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 = "landuse"

# Execute Exp
outExp = Exp(inRaster)

# Save the output
outExp.save("C:/sapyexamples/output/outexp")``````

## Licensing information

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