[gdal-dev] gdal_calc.py floating point arithmetic

[Sam Wilson]

Hi,

I’m attempting to linearly interpolate two geotiff files using gdal_calc.py.  The geotiff files are 3 hours apart, so for example hour 0 and hour 3.  I’d like to end up with hourly data, so I need hours 1 and 2.

Below are the commands I’m using:

gdal_calc.py -A hour0.tif -B hour3.tif —outfile=hour1.tif —calc=“(A+B)*0.333”
gdal_calc.py -A hour0.tif -B hour3.tif —outfile=hour2.tif —calc=“(A+B)*0.667”

However, hour1.tif and hour2.tif appear to be the exact same.

Does gdal_calc.py not allow using floating point values in the calculation? Or, am I doing something else wrong?

Many thanks.

Sam