GammaLib

Addition and subtraction operators shall be added to GSkymap that allows adding or subtracting the content of one map to the content of another map. The operators should work on maps of different size, doing an effective reprojection of the map by bi-linearly interpolating the map values between the pixel centres.

Below a typical example:

GSkymap coarse("CAR", "GAL", 0.0, 0.0, 0.1, 0.1, 100, 100, 1);
GSkymap fine("MER", "GAL", 0.0, 0.0, 0.01, 0.01, 1000, 1000, 1);
fine += coarse;
fine = fine - coarse;