We sometimes need to set the coord fields of a source catalog, e.g. when fitting a new WCS or when studying an `icSrc` catalog (whose Coord field is not set). It would be nice to have a central, easily found way to do this. Right now we have the following as a static method of `TanSipWcsTask`, which works fine but is in a poor location:
The other direction is also useful for reference catalogs, though from a practical standpoint the only user is probably `meas_astrom`. Even so, I suggest that this be made publicly available in the same way. Again, this is presently a static method of `FitTanSipWcsTask`:
I hope this can remain Python code, but admit that the extra speed of C++ might come in handy in some cases. In any case, once the function is in a central location we can implement it in C++ if we find the need.