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

Radim Blazek blazek at itc.it
Tue Jun 18 04:22:44 EDT 2002

> [GRASSLIST:3899] Re: m.in.e00: Attaching cat labels to lines.
> I suspect that the initial design of Grass does not support well mixed
> (areas and lines) vector files, because labels are common to areas and
> lines. 

I think that it is possible to mix areas and lines in one map 
(and I used taht many times), also in progman 6.7.5 is:
5. It is recommended that area features and linear features be placed in 
separate layers. However if area features and linear features must appear in 
one layer, common boundaries should be digitized only once. 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.

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.

On Tuesday 18 June 2002 09:55 am, Michel Wurtz wrote:
> I have corrected a bug in m.in.e00 that prevented the line
> attributes to be correctly placed, and produced lot of errors
> when running v.support.  This should now be correct.
> I've modified release_branch and main trunk.


> One problem remains : if there is a line with a dead end,
> the area in which it is cannot be labelled (BAD in the
> exemple bellow).
>  +----+-----+-------+
>  | +  +     |  + OK |
>  | BAD      |       |
>  +----+-----+-------+
> Should I add a flag to indicate if you want a line or an area
> result ? This can be done with the "type=..." parameter and can
> lead to a better interpretation of e00 input :
> line => no area attributes, only line attributes (actually not
>         working : adding area attributes erases line attributes)
> area => suppression of lines with the same left and right area
>         (so v.support will work better), only area attributes

Yes, useful.

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.


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