Radim,
I am copying you on this as you seem the primary expert. I copy my notes and error messages below. Essentially, while I managed to create a closed area, I can't yet get any data associated with it in GRASS 5.7. I can export it to GRASS 5.0.2 and do this without a problem. Either, I am simply missing some essential concept, this is a bug in the code, or there is something missing from the version of 5.7 that I have. After several hours of messing with it, I can't tell which of these it is.
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C. Michael Barton, Professor
Department of Anthropology
PO Box 872402
Arizona State University
Tempe, AZ 85287-2402
USA
Phone: 480-965-6262
Fax: 480-965-7671
- - - more GRASS 5.7 test notes - - -
Preface:
I tried a lot of things to associate some kind of table with a closed polygon I have created in GRASS 5.7--including working in v.digit and experimenting with the v.db and db. commands. My current goal is to 1) create a polygon in v.digit, 2) associate with a single category of information, and 3) output it to a raster file. (For the curious among you all, I am using this as a mask to create a 'hole' of null values for a network of barrancos/ravines in a DEM. I am then using r.fillnulls--still only in 5.0.2--to create a model of the terrain before the barrancos were eroded. Since I needed to do this anyway, I thought it would be a good excercise to try out several capabilities of version 5.7.)
Please note that I am not a DBMS novice, but have developed applications of at least passable sophistication in x-base (dBase and FoxPro) and more recently in Filemaker. I have PostgreSQL up and running and have used it with GRASS on a test basis. However, for most of my needs, the internal database in the new GRASS 5.7 will serve much better currently than a PostgreSQL/PostGIS or even ODBC connection (though one to Filemaker would be nice eventually). So this is why I am trying to get it to work smoothly. I understand conceptually (or at least **think** I do) how the new vector format interfaces with various DBMS, including the internal one--and like it. Also, I am comfortable with DBF and it will allow me to rather seamlessly transition data from MapInfo and ArcView--both of which maintain attribute data in dbf formats.
This background, of course, does not prevent me from completely and stupidly missing some important point here which may be patently obvious to everyone else 
11/2/03
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OK, I exported my area to an ascii file (v.out.ascii) and reimported it. Ran v.build. Then ran v.digit and created an associated table. It seems to have an attached database and table now (checked with v.db.connect.)
It will let me output to a raster file, but nothing in the raster file (i.e., NO DATA and nothing visible in d.rast). Tried to run v.category to add something to the category field in the hopes that this might solve the problem. Did the default using the same input and output files (i.e., overwrite original). Here is the result.
v.category input=polop_barranc2 output=polop_barranc2 type=area option=add cat=1 field=1 step=1
WARNING: Vector 'polop_barranc2' already exists and will be overwritten.
0 new centroids placed in output map
DBMI-DBF driver error: (null)
WARNING: Cannot open select cursor: 'select * from polop_barranc2'ARNING: Cannot copy table
Registering lines:
2 primitives registered
Building areas: 50%100%1 areas built
1 isles built
Attaching islands: 100%
Attaching centroids: 50%100%
Number of nodes : 2
Number of primitives: 2
Number of points : 0
Number of lines : 0
Number of boundaries: 1
Number of centroids : 1
Number of areas : 1
Number of isles : 1
>>>>>>>>>>>>>>>>>>>>>>>
Do I have a problem with the version I have in the dbmi drivers or am I just doing something wrong. I've reread the tutorial sections that seem appropriate and I can't find the answer there.
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