[GRASS-dev] null value in vector (v.in.ascii, v.surf.*)

Hamish hamish_b at yahoo.com
Thu May 16 00:15:28 PDT 2013


Yann:
> Does this mean that v.in.ascii recognizes 99999.99 as a grass
> vector null value?
> 
> If I use 99999.99 in v.surf.* will it be discarded from the
> interpolation?

Nope, the 'grep -v' means that entire row of data is excluded
from the datastream and never sent to v.in.ascii in the first
place.

I just used NULL=99999.99 as an example, NULL= could be set to
anything.


If you need the x,y row there, but with empty values instead of
9999s in some column, then db.execute might be a faster way
than v.db.update to clear them (only open and close the DB once),
but v.extract with where="value < 9998" might be fastest of all.


Hamish


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