Other places that use `abs` as opposed to `std::abs` for floats/doubles that could be affected:

[KrisThielemans]

Following from #1409, we need to check other places that use abs for floats/doubles that could be affected. Simplest is to just replace them with std::abs, but it'd be good to know if there was a problem or not. I guess easiest might be to put an error abs(1.5)-1>.2 while checking.

Copying from #1409 (comment)_

Library: (worrying!)

• ProjDataInfo::get_sampling_in*: are not affected, but I don't know why
• inverse_SSRB
• extend_projdata

Utilities:

• shift_image (maybe not due to #include <math.h>)
• find_fwhm_in_image.cxx (possibly not due to using namespace std;)

Relatively harmless as error checking:

• ExamInfo::operator==, - Radionuclide::operator==
• TimeFrameDefinitions::operator==
• error checking in ProjMatrixByBinSPECTUB
• error checking in ProjMatrixByBinUsingRayTracing

Test code:

• test_interpolate_projdata.cxx
• test_blocks_on_cylindrical_projectors.cxx

Commented out code, hence harmless (but confusing):

• warp_image

[markus-jehl]

The inverse_SSRB tests still pass even if the expressions passed into abs() are cast to integers before. I think it would require some quite elaborate design of the scanner rings and downsampling to find a case where the logic would be vulnerable to the int conversion. Nonetheless, it would definitely be saver to switch to std::abs.