# Exp (Image Analyst)

## Summary

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

## Usage

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

• 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.

## 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.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.ia import *
env.workspace = "C:/iapyexamples/data"
outExp = Exp("landuse")
outExp.save("C:/iapyexamples/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 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 = "landuse"

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

# Execute Exp
outExp = Exp(inRaster)

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

## Licensing information

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