1

I have been using QGIS Raster Calculator to patch Raster Bs values in where Raster As are 0 using the below expression

("A@1" = 0) * "B@1" + ("A@1" != 0) * "A@1"

I now want to do this using gdal_calc within a python script, but it keeps throwing up the error that my formula is an invalid syntax. How can I achieve the same results?

gdal_calc --calc "(A = 0) * B + (A != 0) * A" --format GTiff --type Float32 -A C:\Users\Public\try\A.tif --A_band 1 -B C:\Users\Public\try\B.tif --B_band 1 --outfile C:/Users/public/OUTPUT.tif
1
  • That was exactly the issue! thanks. Can you put this as the answer so I can accept?
    – user196963
    Commented Nov 30, 2021 at 21:41

1 Answer 1

2

gdal_calc uses python syntax. In python = is used for variable assignment and == is for equality checking.

E.g.

>>> a = 123   
>>> print(a)
123 
>>> a == 123
True
>>> a == 1234
False

So the following should work:

gdal_calc --calc "(A == 0) * B + (A != 0) * A" --format GTiff --type Float32 -A C:\Users\Public\try\A.tif --A_band 1 -B C:\Users\Public\try\B.tif --B_band 1 --outfile C:/Users/public/OUTPUT.tif

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.