v.support on digitized data

Stuart Bradshaw lewis!bradshaw
Thu Dec 17 15:49:38 EST 1992


> I have recently digitized landuse areas using v.digit.  On running v.support
> I get the following error message:
> 
>     Warning:  area 141 label: 205 matched another label 205
>     Warning:  area 143 label: 201 matched another label 205
> 
>        # of lines: 272
>        # of nodes: 271
>        # of areas: 272
>        # of isles: 271
>        # of atts: 402
>        # of unattached atts: 0
>        Snapped lines: 0
> 
> After running v.clean on the data, I still got the same warnings.  What does 
> this mean and how do I fix the data.  There are many of these warning 
> messages.


As I understand, these warning messages are because of duplicate labels that
exist in the dig_att/your_file_name.   If you have a digit file which you have
edited (say change some labels, add some new lines -thus breaking up an existing
polygon and making new ones, and subsequently labeling these) the labels ("attribute") file will be maintained.  The dig_att file records the label type, the x,y and
the label number. Sometimes the file will end up with labels that have the same x,y
or fall within the same area. v.support flags this as a Warning:   But from what
I've seen this isn't a problem because the program always uses the most recent 
label put in or edited.

I don't think there is a program to remove these labels and v.clean doesn't do
the job because it only removes the "dead" lines from the actual digit file.



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