[GRASS5] m.in.e00 updated and some questions

Michel Wurtz mw at teledetection.fr
Tue Jun 18 05:51:02 EDT 2002


Radim Blazek wrote:
[From Progman...]
> ...An area edge that
> is also a line (e.g., a road which is also a  eld boundary), should be
> digitized as an area edge (i.e., arc type A ) to complete the area. The area
> feature should be labeled as an area (i.e., feature type A in the dig_att
> le). Additionally, the common boundary arc itself (i.e., the area edge which
> is also a line) should be labeled as a line (i.e., feature type L in the
> dig_att  le) to identify it as a linear feature.

Yes, but I have noticed that opening dig_att file for updating it erase
all the previous content.  I wonder if this grass lib "feature" must be
changed...  I will try to have a closer look at the library and maybe
propose some change (opening for writing may clean the file, but not
opening for updating...)

> If you mean dig_cats by labels, then you are right, if lines and areas
> have the same category numbers, category labels may not differ.

Yes.

[...]
> Other possibility could be, to import dangles as grass type line, then
> both lines and areas could be imported, and v.support should not fail.

Yes, this will also work... if one can write mixed dig_att file, as I say
above...

--
Michel WURTZ - DIG - Maison de la télédétection
               500, rue J.F. Breton
               34093 MONTPELLIER Cedex 5



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