Possible issue in get_dp0_images function

[aesar77]

Hi,

I was using get_dp0_images function to create coadd cutouts. However, mag_zero_point array is always empty. When I traced back the issue, I figured that

   if not coadd_injection:
        visit_info = coadd_image.getInfo().getCoaddInputs().ccds
        index = np.random.randint(0, len(visit_info))
        dataId_visit = {
            "visit": visit_info[index]["visit"],
            "detector": visit_info[index]["ccd"],
            "band": visit_info[index]["filter"],
            "tract": tractInfo.getId(),
        }
        visit_image = butler.get("calexp", dataId=dataId_visit)
        coadd.append(visit_image)
        variance_map.append(visit_image.getVariance())
        mag_zero_visit.append(
            2.5 * np.log10(visit_image.getPhotoCalib().getInstFluxAtZeroMagnitude())
        )
    else:
        coadd.append(coadd_image)
        variance_map.append(coadd_image.getVariance())
        coadd_nImage.append(butler.get("deepCoadd_nImage", dataId=coaddId))

If coadd_injection is True, mag_zero_visit array is not updated, so it is returned empty. Also, there is a warning on multiple_lens_injection.ipynb in which lens_inejection_fast function is called, that calls get_dp0_images ,

warnings.warn( ../notebooks/.local/lib/python3.12/site-packages/lenstronomy/Data/psf.py#line=94): UserWarning: Input PSF model has at least one negative element, which is unphysical except for a PSF of an interferometric array.

I suspect it might be due to this problem, since image_simulation gives sim_api mag_zero_point in kwargs_band, which is given to data_util.magnitude2cps() function as far as I've followed in lenstronomy.

[sibirrer]

Tagging @nkhadka21 here :)