missing values in attribute field (excel import)

443
0
05-02-2012 12:48 PM
MarkShadden
New Contributor
I have a variable, X, in an Arc file that I would like to copy as another variable, Z.  The data is from a replication dataset using a raster grid.  The original observations on X were a sample of grid squares, aprox. 300 out of 1,300 grid squares, taken from a survey.  The original authors interpolated the remaining 1,000 observations using IDW.  I am attempting to replicate their study, but using various methods of interpolation to show sensitivity in their findings.  The problem is that in their replication data for X they include the interpolated values in the vector/column/variable with the observed survey values of variable X.  I need to copy X and take out the interpolated values so that I may re-interpolate them using different methods.  I have attempted to do this in two ways.  First, I exported the data to excel, took the appropriate steps, then imported the data back into ArcGIS.  However, Arc now only recognizes it as a String because the missing values are entered as "<NULL>".  I have not found a way to correct this.  Second, I generate a new variable in ArcCatalog, Z, and Arc fills in all the observations with zeros.  Now, I cannot figure out how to copy and paste X into Z and then delete the interpolated values in Arc.  I have found some posts on message boars that suggest using the "Attributes dialog box", but none of my variables (attributes?) show up in the box.  Any suggestions?  Thank you.
Tags (2)
0 Kudos
0 Replies