[GRASSLIST:7233] Boundary Corner Extraction

Brian Ferris bdferris at u.washington.edu
Mon Jun 20 01:31:59 EDT 2005

I'm new to Grass and GIS in general and I've been working with a  
dataset giving boundary data for buildings in Seattle.  I'm  
specifically attempting to determine the coordinates of one building  
in particular and I'm at a loss for the best way of extracting this  

So far I've tried the following:

1) I tried querying the particular boundary with the d.what.vect  
command.  While the building has ~15 points defining its perimeter,  
the boundary seems to be defined by three nodes (I'm assuming nodes  
and points are the same thing?).  The three nodes seem to define  
starting points for three sections of the total building perimeter.   
While the d.what.vect command tells me the location of those three  
nodes, it does not tell me the corners.

2) I tried converting the boundary into lines using the v.type  
command, but the resulting lines seemed to be define in the same way  
as the boundary above (three nodes; no corner information)

3) I've tried exporting the vector to CSV using v.out.ogr, but the  
resulting output lists only attribute values and not the actual  
boundary definition.

Any advice?  Thanks for your help.

Brian Ferris

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