Field Calculator Woes

Discussion created by bdbacca on Feb 26, 2011
Latest reply on Feb 28, 2011 by bdbacca
Alright, I'm trying to model a watershed district for surface flow and I'm up to the CN grid. I have most of it completed, merged my land use polygons with the soil type and ranked the soils A-D but now I'm trying to calculated the soil type for each polygon and the field calc has me thrown for a loop.

I have columns of "polygon_area", "Hydgroup", "PctA", "PctB",.."PctD" . I have 1684 rows and REALLY don't want to do this the brute-force method so I opened up the field calc and typed in:

if [Hydrgrp] = "A"
  [PctA] = 100

My hope is that it will scan the column, find the true statements, then fill in the column with the value of 100. If the row says "B" (or c/d), the statement would be false and either be left blank or filled with 0. (I know how to use the ELSEIF function a la Matlab also)

My question is if I throw the above into the Pre-Logic VBA Script code box, there is still a box below with the leading "PctA = " and I can't run the calculator without something in that field. If I put my IF statement in there, I get the "Error running VBA code: User interrupt" message. If I put an integer value in this lower box, it fills my entire column with that value without my IF filter.

What's the deal?!
ArcGIS 9.3 with GeoHMS toolbars installed on a Windows 7 PC.

Also, I tried to setup the IF statement where it would use:
[hydgrp]/"A"= aValue
  aValue=1  in the VBA box then in the lower box, PctA= aValue*100 but that gave the same error as above.

I don't understand how to run the calc with a VBA script then the equation bar. :-/

I'd appreciate any help/guidance!