GRASS to ARC

dgc at cast.uark.edu dgc at cast.uark.edu
Thu Feb 29 07:00:00 EST 1996


Hello all,

        I have been having some problems with the GRASS 4.1 module v.out.arc.  
I have a vector map that I would like to export to ARC/INFO.

        The problem is that the labels are not translating correctly over to 
ARC/INFO.  It came out of GRASS with 99,136 polygons (with label coordinates an
d
labels).  When the map is built in ARC/INFO it has 106,354 polygons and ARC/INF
O
automatically assigned the extra 7,218 polygons a User-ID of zero.  The 
problem occurs when the joinitem command is issued, to link the labels to the 
polygons (from GRASS outputs mapname.lab & mapname.txt).  The joinitem does not
link correctly (and I think it is because of these 7,218 extra polygons which
I do not have labels for because they weren't in the original map).

        I think I may have found the problem but I am not sure and would like
some assistance.  The mapname.pol file (that has the polygon attribute
number and the X Y coordinates for the nodes) has what I think are errors.  Her
e
is a clip

1
    754621.39   4042740.00
    754591.39   4042740.00
END
2
    754711.39   4042740.00
    754621.39   4042740.00
END
3
    754801.38   4042740.00
    754711.39   4042740.00
END
4
    754411.39   4042710.00
    754411.39   4042740.00
    754591.39   4042740.00
END

The first three polygons are actually lines, not closed polygons.  The 
ARC/INFO manual says that if the first node is not repeated at the end of the 
polygon, it assumes that is were the polygon closes, but it can't close a line 
segement (which the first 3 are).  Is this a GRASS problem or an ARC/INFO
problem ? As I said, I am a bit confused and any assistance would be helpful.
                Don


-----------------------------------------------------------------------------

Don Catanzaro                                           |
Graduate Assistant                                      |Phone: (501)-575-6159
Center for Advanced Spatial Technologies                |     : (501)-575-6536
12 Ozark Hall                                           |Fax  : (501)-575-5218
University of Arkansas                                  |e-mail:
Fayetteville, Arkansas  72701                           |dgc at CAST.uark.edu

        "Part of working for a living is working for a world to live in"
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