[GRASS5] GRASS 6 capabilities?

[John Gillette]

I can't reproduce this using Grass5.3 CVS 07/31/2004.  I used the
following 2 diamond shaped polygons:
--------------------------
ORGANIZATION: 
DIGIT DATE:   Thu Aug 12 08:37:13
DIGIT NAME:   
MAP NAME:     guilf_level
MAP DATE:     
MAP SCALE:    2400
OTHER INFO:   
ZONE:         0
WEST EDGE:    1748000.000
EAST EDGE:    1752000.000
SOUTH EDGE:   810000.000
NORTH EDGE:   812000.000
MAP THRESH:   0
VERTI:
A  5
 811000   1750000 
 812000   1751000
 811000   1752000
 810000   1751000
 811000   1750000
A  5
 811000   1750000
 810000   1749000
 811000   1748000
 812000   1749000
 811000   1750000
-----------------------------
A 1751000.000000 811000.0000000          1       
A 1749000.000000 811000.0000000          2       
-----------------------------
# 2 categories


0.00 0.00 0.00 0.00
1:forest
2:water
----------------------------
V.SUPPORT:

Selected information from vector header
 Organization:  
 Map Name:      guilf_level
 Source Date:   
 Orig. Scale:   2400
 Snapping threshold    0.00
  No snapping will be done.
    Reading Vector file
    Building areas
    Building islands
    Attaching labels
 Number of lines:   2
 Number of nodes:   1
 Number of areas:   2
 Number of isles:   1
 Number of atts :   2
 Number of unattached atts :   0
 Snapped lines  :   0
--------------------------------
Note that there are 2 areas detected and using d.what.vect, I can see
Category 1 forest or category 2 water.  Both polygons share 1 node.

Is this what you meant?

John
 

-----Original Message-----
From: grass5-admin at grass.itc.it [mailto:grass5-admin at grass.itc.it] On
Behalf Of Roger Miller
Sent: Thursday, October 27, 2005 8:05 PM
To: grass5 at grass.itc.it
Subject: [GRASS5] GRASS 6 capabilities?

Folks,

I have frequent problems when importing vector files prepared with ESRI
products to GRASS5.x  If two or more polygons share a node then GRASS5.x
supports them as a single polygon.  Errors are generated in v.support
because GRASS5.x sees multiple attributes associated with one polygon.
Any subsequent operation that needs to identify the imported polygons
tends to produce useless results.

The only way I know of to fix the problem after the polygons are
imported is a difficult process.  I have to export the polygons as ascii
files, identify polygons that share identical nodes and rotate the
sequence of points in one or more polygons so that all of the polygons
start and end at unique points.

I know this isn't a bug, but it is an unfortunate feature of GRASS5.x
that has caused me hours of work and cost my clients money.  Is this
problem fixed in GRASS6.x?


Roger Miller 

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