NoData in ArcGIS Spatial Analysis

Question

When using Spatial Analyst I regularly have issues with NoData values cropping up in the data. Various tools appear to introduce NoData values regularly. These values then cause issues with other tools and have to be eliminated with reclassification, usually resulting in other problems.

How should NoData values be dealt with? Is there a simple way to replace NoData values with zero? Can NoData be avoided altogether?

Answer 1

I would have used the raster calculator with the following expression:

Con(IsNull([raster]), 0, [raster])

It assumes that your raster is called 'raster'.

Answer 2

You can set NoData values to any value using the conditional operator Set Null ( ArcGIS 9.3, ArcGIS 10). I'm not aware of a way of preventing the NoData from appearing in the first place, though.

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I realized I should have written/linked to the Con operator as @AndOne mentioned.

From the documentation, if you use python:

import arcpy
from arcpy import env
from arcpy.sa import *
env.workspace = "C:/sapyexamples/data"
outCon = Con("elevation", "elevation", "", "VALUE > 2000")
outCon.save("C:/sapyexamples/output/outcon.img")