[GRASSLIST:6399] use of c_minx and c_maxx in r.series

vincent at ecovla.nl vincent at ecovla.nl
Mon Apr 11 10:23:30 EDT 2005

Hi all,

first I want to thang Glynn for writing those functions (c_minx and
c_maxx) for r.series; I had just concluded I would have to write them
myself. Now for the use of these:

What I need, is to be able to extract the values of a certain band in a
series of images, according to where the value is lowest in another
band. E.g. I have a annual series of images, one per month, red and nir
bands, and I want to have not only the lowest values of the nir band,
but also the values of the red band that correspond with the images
those lowest nir values were taken from. Or, in other words, get an
index raster for the lowest nir values (1 means value from the first
image is lowest for this pixel, 2 means take value from second image,
and so on), and use this index not only on the nir band but also on
other bands.

Now with Glynns functions I'm already half-way: I can create the index.
Now how do I apply this index to a series of raster files? Is there a
simple and robust (like accepting input from g.mlist) trick using
r.mapcalc? Or is Glynn currently writing r.series.fromindex and am I too
anxious and should I be patient? Or need I write it myself? Any hints?


More information about the grass-user mailing list