[GRASSLIST:350] Re:Re: using v.patch

[michele.rocc]

> Hello Michele

Thanks, now it's clear to me the warning message, anyway
my contours lines were imported correctly.
  
> This would be because v.in.dxf and v.in.dxf3d don't create a category
> file (dig_cats); they store all the categories in the attributes file
> (dig_att). If the categories are all positive integer numbers (e.g.
> contours above sea level) this is probably all right and nothing much to
> worry about then.
> 
> And if they are contours then it will even be useful when you are
> running v.patch as the contours in the different files with the same value
> will have the same attribute number and they will all patch together
> cleanly.
> 
> But if you have positive floating point numbers v.support will truncate
> them to integers, and it will delete any other categories (e.g. zero or
> text values). It does this without warning.
> 
> With help from John Gillette I had prepared a patch for v.in.dxf and
> v.in.dxf3d so it would put a unique number in the dig_att file for each
> category and write the category to the dig_cats file. But I didn't apply
> it to GRASS as I wasn't sure this was the best way of solving the problem.
> For example, it would mess up the output of v.patch as the same attribute
> number might correspond to different categories in the different input
> files.
> 
> In short, if your DXF files contain contours and there were no 0 or
> negative values, it should be OK.
> 
> Paul
> 
>