Hi all, have doubts in how to proceed in Grass: Have Modis ndvi raster imges
and want to get the ndvi value of 4 (different) crop areas, do the same for
several years. Then I want to put this data down into a spreadsheet to make
a regression analysis.
Which command shall I use to get this values? g.region to set the specific
region but then feel confuse of which command should be use to get the pixel
values of the area. MANY THANKS
If you have the crop areas as a polygon vector map, then v.rast.stats is probably what you’ll want to use. If the crop areas are point locations, then v.what.rast gives the raster value at point locations.
···
On 08/29/2013 03:35 PM, Lbxa wrote:
Hi all, have doubts in how to proceed in Grass: Have Modis ndvi raster imges
and want to get the ndvi value of 4 (different) crop areas, do the same for
several years. Then I want to put this data down into a spreadsheet to make
a regression analysis.
Which command shall I use to get this values? g.region to set the specific
region but then feel confuse of which command should be use to get the pixel
values of the area. MANY THANKS
-----
Lbxa
--
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Finally, after few issues in my computer, I got the commands v.what.rast &
v.rast.stats working! I worked very well in Grass7..... but no in Grass
6.42, not sure what did miss here. Thanks
Finally, after few issues in my computer, I got the commands v.what.rast &
v.rast.stats working! I worked very well in Grass7..... but no in Grass
6.42, not sure what did miss here. Thanks
Hi,
you'll have to supply us with more information about what you tried and
what wasn't working about it.
also you might check to see if it is already fixed in the new 6.4.3 release.
When I wanted to edit the attribute table of my vector map I got the
following message: "Database connection for vector map <testvectmap@us1> is
not defined in DB file. You can define new connection in 'Manage layer tab'.
I clicked "OK", but the 'Layer of vector map' doesn't allow to click in any
option. So, I couldn't go any further. Could not edit or add any attribute.
My vector map is a csv file with x,y (coordinates values) and q (attribute
value).
I proceeded the same way in Grass7 and didn't have this issue.
When I wanted to edit the attribute table of my vector map I got the
following message: "Database connection for vector map
<testvectmap@us1> is
not defined in DB file. You can define new connection in 'Manage layer
tab'.
I clicked "OK", but the 'Layer of vector map' doesn't
allow to click in any
option. So, I couldn't go any further. Could not edit or add any attribute.
My vector map is a csv file with x,y (coordinates values) and q (attribute
value).
I proceeded the same way in Grass7 and didn't have this issue.
Are you using GRASS 6.4.2? If so please upgrade to 6.4.3 where I think
that is fixed.