Dear Michaela,
Thanks! Nothing really goes wrong.
My code looks similar to yours:
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v.in.ascii -z input=inputFile output=outputMap fs='\t' x=LON y=LAT z=PAR
v.surf.idw input=outputMap output=interpolatedRaster npoints=3 layer=1 col=dbl_5
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Since I have already selected the column in v.in.ascii by putting z=PAR (which is an integer coming from the GRASS parser and indicating the column of the ascii file I want to interpolate), how can I get get the right column while batch processing with v.surf.idw based on PAR (i.e., an integer stored in a bash-shell variable)?
Currently I can't do it, so I have to open the attribute table of my v.in.ascii-imported vector map and guess what is the right column name to put in v.surf.idw (col=dbl_5 in my sample code), since the original column names are not there anymore (as to GRASS 6.0.0, v.in.ascii does not accept column names and I have to get rid of them via a perl script).
In contrast, when using v.surf.rst there is no column specification, you just have the imported vector map as input parameter and that's it. That is, v.surf.rst figures out what to interpolate: obviously the z column, since the input it's a 3D vector map. However, v.surf.idw needs the attribute table column as an additional input.
Have you figured out a way to automate this step?
What is col=dbl_310.8606 47.3936 4000 100.6? It looks like a row not a column of you data sample.
Ciao and thanks again for any hint,
Luigi
Michaela Kinberger wrote:
dear luigi,
i´am also using v.surf.idw (grass6.0.1 suse rpms, and OSX) in batch mode. everything works fine.
some lines of my code:
v.in.ascii -z input=file2.txt output=werte_red z=3 fs=' '
v.surf.idw input=werte_red output=surf_red col=dbl_310.8606 47.3936 4000 100.6
this is what the input looks like:
x y z value
10.7809 47.5606 4000 128.2
11.0068 47.4074 4000 99
11.0618 47.4352 4000 135
11.3792 47.3069 4000 147.48
11.7633 47.4425 4000 139.04
11.8919 47.6629 4000 173
12.3516 47.7543 4000 174
what goes wrong in your script? is there any error message?
lg
michaela
Luigi Ponti wrote:
Hello,
I am trying to use v.surf.idw instead of v.surf.rst because it seems to suite better my 105 unequally spaced weather stations in California in terms of interpolated raster: the range of the data is respected and there is no issue of tension and smoothing.
I wrote a script to batch-process a series of tables containing geo-referenced data that I import via v.in.ascii for subsequent interpolation.
Whith v.surf.rst the imported vector with data points is the only input and the appropriate attribute column has already been selected while importing via v.in.ascii by putting the correct column number=z.
However, whith v.surf.idw, in addition to the input vector, there is also a "col" string parameter which selects an attribute table column. So far, I have to open the DBF attribute table (where there are not just 3 columns) and figure out a weird column name such as "dbl_4" that matches the column I want to interpolate (that I have already chosen when importing with v.in.ascii).
Why v.surf.rst can access the right column without any other specification and v.surf.idw cannot? Is there a fix for batch processing?
Thanks,
Luigi