Mask
Release 9.2 Last modified September 4, 2007	Print all topics in : "Raster Analysis settings"

Identifies those cells within the analysis extent that will be considered when performing an operation or a function. Setting an analysis mask means that processing will only occur on selected locations and that all other locations will be assigned values of NoData.

Setting an analysis mask is a three-step process:

• An analysis mask must first be created if you do not already have one. It can be a raster or a feature class dataset.
  
• If the analysis mask is a raster, all cells of interest have a value, and all other cells have a value of NoData. Only cells with values will be considered in the analysis. The Reclassify tool can help create a raster analysis mask.
  
• If the analysis mask is a feature dataset, only locations containing features will be considered in the analysis.
  

Illustration

Usage tips

• The keyword used at the command line or in scripts for this environment setting is Mask.
  
• Rather than creating the mask based on attributes, you can specify a spatial boundary as the mask. Create a new feature dataset (in ArcCatalog) and digitize the spatial boundary in ArcMap.
  
• Learn more about masking
  
• Learn more about specifying raster analysis settings
  
• Learn more about environment settings
  
• Learn more about environment levels and hierarchy
  

Command line syntax

An overview of the command line window

Mask <raster_dataset>

Parameters	Explanation	Datatype
<raster_dataset>	A raster dataset in which all cells of interest have a value, and all other cells have a value of NoData.	Raster Dataset

Data types for geoprocessing tool parameters

Command line example

Mask H:\Tongass\oldgrowgrid

Scripting syntax

An overview of scripting in geoprocessing

Mask (raster_dataset)

Parameters	Explanation	Datatype
raster_dataset (Required)	A raster dataset in which all cells of interest have a value, and all other cells have a value of NoData.	Raster Datatset

Data types for geoprocessing tool parameters

Script example

import arcgisscripting
gp = arcgisscripting.create()

gp.workspace = "h:/workspace"
gp.toolbox = "SA"
gp.Mask = "H:/Tongass/oldgrowgrid"

Please visit the Feedback page to comment or give suggestions on ArcGIS Desktop Help.
Copyright © Environmental Systems Research Institute, Inc.