def test_find_nearest_component(self):
self.components = create_low_test_skycomponents_from_gleam(
flux_limit=0.1,
phasecentre=self.phasecentre,
frequency=self.frequency,
polarisation_frame=PolarisationFrame('stokesI'),
radius=0.5)
match, sep = find_nearest_skycomponent(self.components[3].direction,
self.components)
assert match.name == 'GLEAM J211146-685527', match.name
def _checkcomponents(self, dirty, fluxthreshold=0.6, positionthreshold=0.1):
comps = find_skycomponents(dirty, fwhm=1.0, threshold=10 * 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])
for comp in comps:
# Check for agreement in direction
ocomp, separation = find_nearest_skycomponent(comp.direction, self.components)
assert separation / cellsize < positionthreshold, "Component differs in position %.3f pixels" % \
separation / cellsize