How to Solve "Points to Area failed" problem

Blanca Shulan Huang blanca at icc.icc.co.th
Fri Dec 27 21:37:12 EST 1996


Hi Pat Luther,

After I import data from Arc/Info, then I did the v.support command to
the vector map which is generated from the v.in.arc process.  If I saw
many "points to areas failed" message, how and what should I do to
correct this result?

The reason that I need to correct the error is: if I ignore these error,
and go ahead to convert the vector file to raster file, the resulted
raster file will not show those areas failed to be converted.  Then I
will get an imcomplete raster map.

I use to try using v.digit command to LABEL the "problem" areas which
missed their label points, but I can't make it right.  How can label an
area which is formed by many single lines?

Please help me to solve this problem.  I am in the process of converting
a big city map from Arc/Info data to GRASS.  And I encounter many
problems.  One of them is data duplication.

The city map data is stored in the Arc/Info system, and was input by
eight people.  Somehow during the data input process, some portion of
one people's job is duplicated with other co-worker's job.  So after I
converted these eight sets of maps to GRASS, and tried to patch these
eight single pieces of maps together to be a complete city map, I found
I must cut off the duplicate portions first before I apply the v.patch
command.

So I cut off the duplicate protions by using v.digit command, then I
apply the v.patch command to patch maps together.  The outlook of the
resulted vecter map looks correct, only some pieces of areas lost their
label points due to the "points to area failed" message.

Regards,

Blanca Huang



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