test_imaging.py 文件源码

def _checkcomponents(self, dirty, fluxthreshold=5.0, positionthreshold=1.0):
        comps = find_skycomponents(dirty, fwhm=1.0, threshold=fluxthreshold, npixels=5)
        assert len(comps) == len(self.components), "Different number of components found: original %d, recovered %d" % \
                                                   (len(self.components), len(comps))
        cellsize = abs(dirty.wcs.wcs.cdelt[0])
        # Check for agreement between image and DFT
        for comp in comps:
            sflux = sum_visibility(self.componentvis, comp.direction)[0]
            assert abs(comp.flux[0, 0] - sflux[0, 0]) < fluxthreshold, \
                "Fitted and DFT flux differ %s %s" % (comp.flux[0, 0], sflux[0, 0])
            # Check for agreement in direction
            ocomp = find_nearest_component(comp.direction, self.components)
            radiff = abs(comp.direction.ra.deg - ocomp.direction.ra.deg) / cellsize
            assert radiff < positionthreshold, "Component differs in dec %.3f pixels" % radiff
            decdiff = abs(comp.direction.dec.deg - ocomp.direction.dec.deg) / cellsize
            assert decdiff < positionthreshold, "Component differs in dec %.3f pixels" % decdiff