topic Re: Use Raster Calculator for Added Attribute Value in ArcGIS Spatial Analyst Questions

Use Raster Calculator for Added Attribute Value

NealBanerjee — Wed, 02 Mar 2011 13:05:41 GMT

Hello,

I have an integer raster that has codes from 1 - 12. I have added a new integer field to the .vat that has a different integer corresponding to each of the 12 value fields. I want to use the raster calculator to perform simple math functions, but want to use the added attribute field rather than the original value field. Is there a way to do this? Ive already tried the syntax [<grid name>].[<added attribute name>], but it didnt work.

Thanks in advance!

Neal

Re: Use Raster Calculator for Added Attribute Value

PatrickTaurman — Wed, 02 Mar 2011 14:14:57 GMT

Hi Neal,

Are you using ArcGIS 10?

Patrick

Re: Use Raster Calculator for Added Attribute Value

NealBanerjee — Wed, 02 Mar 2011 15:04:59 GMT

Im using 9.2.

Thanks
Neal

Re: Use Raster Calculator for Added Attribute Value

PatrickTaurman — Wed, 02 Mar 2011 15:34:18 GMT

Can you send me the syntax you are using in the Raster Calculator? Also by didn't work, do you mean it failed and you got an error, or it worked, but the output is not what you were expecting? If it failed, what error did you get?

Re: Use Raster Calculator for Added Attribute Value

NealBanerjee — Wed, 02 Mar 2011 16:49:56 GMT

Sure thing, syntax in raster calculator is below. The name of the GRID is "lufumod3" the name of the attibute field in the raster attribute table is "pctimpv". In this simple case just trying to create a temporary grid equal 3 times the "pctimpv" value

[lufumod3].[pctimpv] * 3

The error I get is:
"the input string is not a geographic or projected coordinate system"

Error code doesnt make any sense to me, but I had assumed it had something to do how it is interpreting the syntax.

One other thing - Im using 9.3 (not 9.2)

Thanks again for looking into this for me

Neal

Re: Use Raster Calculator for Added Attribute Value

PatrickTaurman — Wed, 02 Mar 2011 16:59:41 GMT

The following syntax works for me:

[rastername].fieldname * 3

You don't need square brackets around the name of the field, so your should look like this:

[lufumod3].pctimpv * 3

Try that and let me know.

Re: Use Raster Calculator for Added Attribute Value

NealBanerjee — Wed, 02 Mar 2011 17:01:44 GMT

That works - thanks again!
Neal

Re: Use Raster Calculator for Added Attribute Value

RobertSchmidley — Wed, 23 Mar 2011 13:58:01 GMT

The following syntax works for me:

[rastername].fieldname * 3

You don't need square brackets around the name of the field, so your should look like this:

[lufumod3].pctimpv * 3

Try that and let me know.

How do you do this in ArcMap 10.0?

Re: Use Raster Calculator for Added Attribute Value

PatrickTaurman — Wed, 23 Mar 2011 16:55:58 GMT

At ArcGIS 10, the Dot Notation does not work in the Raster Calculator. Please see the thread here. There is an enhancement request for this functionality.

Patrick

Re: Use Raster Calculator for Added Attribute Value

RobertSchmidley — Wed, 23 Mar 2011 18:46:42 GMT

At ArcGIS 10, the Dot Notation does not work in the Raster Calculator. Please see the thread here. There is an enhancement request for this functionality.

Patrick

Patrick,

THANKS!