[GRASSLIST:3267] Re: Understanding the v.out.ascii output.

[Eric G. Miller]

On Thu, Feb 28, 2002 at 09:35:44PM +0000, Antonio wrote:
> Hi.
> 
> I would like to write a little sed script which adapts the v.out.ascii
> format tothe GMT psxy command format. Obviously I have to first figure
> out how v.out.ascii writes it's format. Nothing is mentioned in the
> man page so hope you can help.  What I done was to export a vector map
> I made for representing my geological formations, 11 categories in
> total. I seem to understand that v.out.ascii export two column data.
> Each vector (area line) is preceeded by I record 'A #' or 'a #' where
> # is a 2-3-4 digit number. How are these 'A #' and 'a #'
> records+correlated to the vectors they rappresent, I mean how can I
> tell by meens of these records which vector is being plotted in the
> ascii file?

Big Letters (A, L, P) mean the data is still "alive", small letters
mean the object has been "deleted".  Running v.support before export
should clean out the "deleted" objects.  There's a little more info
in the programmer's manual. Basically, it's object type (Area, Line,
or Point) number of vertices, then lines of vertices.  Note, 
coordinates are in y,x order and point types always have two
vertices (a degenerate line, actually), so no number is needed.

-- 
Eric G. Miller <egm2 at jps.net>