Greetings,

[Susan Huse]

> I hoping someone can help me with this. 
> 
> I'm having a few problems with v.support.  Occasionally, v.support will return
> errors when run after editing linework. Upon exiting v.digit, I run v.support to
> build new topology and get the following error messages:
> ==============================================
>   Building areas
>     Building islands
>     Attaching labels
> PNT_TO_AREA failed: (-22928.293381, 2328298.233617) (Category 2)
> PNT_TO_AREA failed: (-285865.336725, 1820096.995142) (Category 57)
> PNT_TO_AREA failed: (-350885.939743, 1860159.241012) (Category 57)
> PNT_TO_AREA failed: (-404478.463559, 1527592.117214) (Category 134)
> PNT_TO_AREA failed: (-399131.708403, 1524785.622589) (Category 134)
> PNT_TO_AREA failed: (-509009.406574, 1424217.991164) (Category 141)
> PNT_TO_AREA failed: (-510129.947177, 1423329.238582) (Category 171)
> PNT_TO_AREA failed: (444027.343043, 1217287.368895) (Category 213)
> PNT_TO_AREA failed: (441750.937226, 1208780.872999) (Category 213)
> PNT_TO_AREA failed: (113621.646197, 1168144.867585) (Category 177)
> PNT_TO_AREA failed: (112299.261130, 1170670.998272) (Category 162)
> PNT_TO_AREA failed: (200610.643394, 1072343.642725) (Category 213)
> =================================================================
> 
> I end up with a map with numerous open areas. Im running GRASS 4.1.2 on Linux
> 1.0 with 16 Megs RAM & 14 Megs of swap.  File size is around 10 megs. I've not 
> seen this behavior with GRASS4.0 before - does anyone have any ideas what's 
> going wrong?. I've also seen v.support fail on a regular basis after using 
> v.proj to move data between UTM and albers projections. Other than these
> instances it seems to work fine. 
> 
The errors mean that either your polygons aren't closing so the attribute
couldn't attach to the area, or you attribute is not within the area it
wants to be.  This is not a problem with GRASS, but a problem with the vector
topology (a feature not a bug if you will).
If you created this with v.proj did the attributes get
translated properly?  
What is this a map of and what coordinate system are you now in?
I ask because the first 7 label points have a negative 1st coord and 
the last 5 have a positive.  Are you really in two hemispheres?

I suggest if the label coordinates make sense that you go back into
v.digit and use Toolbox Display Open Area Lines or Display Unlabeled 
Areas.  This will help you find the problems.  You can also use 
Window where am i? to point and click to the approximate location of
your label point to determine which areas are failing.  Then you
need to clean the area (snap nodes, create nodes if lines cross, etc).
When all of the topology is cleaned then exit v.digit and re support
the file.  Repeat until all errors are gone.

> On another subject - is it possible to change the colors of the bounding box 
> used for zooming both inside and outside of v.digit?  My box always seems to
> be a variation of black on black.  Kinda hard to see.
> 
Out of my expertise here, I don't think this is a v.digit problem, but 
rather a problem with your color mapping(?) in GRASS.  zoom boxes should
set the color to something visible no matter what the background.  Have 
you tried to reset the background color in v.digit (Customize Color Background)
You might be able to outsmart the problem.

> Any advice is appreciated.  Thanks for all replies. 
> 
> 
> 						-Ted Cox
> 						 USDA/SCS
> 						 Palmer, Alaska
> 						 astec at acad2.alaska.edu 
> 
> 
>

If you need more specific help on cleaning vectors in v.digit you
can email me directly

sue at ced.berkeley.edu

Sue Huse
CEDR - REGIS 
UC Berkeley