st: mergepoly error

["Bowser, William (IITA)" <W.Bowser@cgiar.org>]

Dear Statalist,

I am trying to aggregate spatial units embedded in a shapefile to generate some maps.  I found the mergepoly command by Robert Picard to be well suited to address this problem, however after running the command on my coordinates data, the following error is returned:


  error . . . . . . . . . . . . . . . . . . . . . . . . .  Return code 9
        assertion is false;
        no action taken;
        Return code and message from assert when the assertion is false;
        see [D] assert.
        Or, you were using mvencode and requested Stata change `.' to #
        in the specified varlist, but # already existed in the varlist,
        so Stata refused; see [D] mvencode.

What could be causing this and how can I make the aggregations with mergepoly or another procedure?

Thanks,

William

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