band skip or specify multiple bands in r.in.gdal

[cmbarton]

In working with NetCDF files, I realize that it is important to be able to skip bands in order to import a coherent data set (e.g., import bands 1,5,9,13.17...). This is especially important when importing times series for the new temporal GIS format in GRASS 7.

There are a couple ways to do this. Assuming that there is a constant band interval (e.g., every 12 bands to import climate data for July for 100 years) a skip argument could be implemented (skip=12 to import every 12th band).

For more control but more work, extending the band= argument to accept a comma separate list could achieve the same result albeit with more typing or cut and past (e.g., bands=1,13,25,37,49,...).

Both methods could be implemented, but the bands= list should probably override the skip= argument in that case.

[neteler]

Perhaps the -b band code of gdal_translate could be inspiring (to pass the band selection on to GDAL):

See

• ​http://www.gdal.org/gdal_translate.html
• ​http://trac.osgeo.org/gdal/browser/trunk/gdal/apps/gdal_translate.cpp#L394
• ​http://trac.osgeo.org/gdal/browser/trunk/gdal/apps/gdal_translate.cpp#L856