st: spwmatrix problems using -import- for .swm

[Andrew Hovel <hovel.andrew@gmail.com>]

I am attempting to merge an .swm file (from ArcGIS) into Stata using
spwmatrix. I keep getting the error that -import- is an invalid
subcommand. I am using Stata 12 IC for Windows.

The spwmatrix command
(http://ideas.repec.org/c/boc/bocode/s457111.html) allows a user to
import .dta, .txt., and .swm files as spatial weights matrixes.

When using  the syntax:
spwmatrix import using "M:\My
Documents\DATA\GIS\Chicago\COOKspatWeight.swm", wname(CHI) swm(TRACT)

I get the error:
>import is not a valid subcommand
>r(199);

I found that someone had a similar issue a year ago:
http://statalist.1588530.n2.nabble.com/import-txt-file-with-spwmatrix-td7580319.html

My first thought is that there may be a problem with the sort order of
the swm file compared to the .dta I already have open--an issue that
arises from the import command.

Another might be that I have more more observations in the .dta open
than in the .swm. Could that also be posing a simlar issue with the
sort order?

Any suggestions for better ways to merge in a .swm file. I have five
cities in a .dta and separate .swm files for each. Is it even possible
to merge five  into one .dta?
*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/faqs/resources/statalist-faq/
*   http://www.ats.ucla.edu/stat/stata/