def test_spectralmagsystem():
"""Check that SpectralMagSystem matches ABMagSystem when the spectrum is
the same as AB."""
# construct a spectrum with same flux as AB: 3631 x 10^{-23} erg/s/cm^2/Hz
# Use a fine grid to reduce linear interpolation errors when integrating
# in Spectrum.bandflux().
wave = np.linspace(1000., 20000., 100000) # fine grid
flux = 3631.e-23 * np.ones_like(wave)
unit = u.erg / u.s / u.cm**2 / u.Hz
s = sncosmo.Spectrum(wave, flux, unit=unit)
magsys1 = sncosmo.SpectralMagSystem(s)
magsys2 = sncosmo.ABMagSystem()
assert_allclose(magsys1.zpbandflux('bessellb'),
magsys2.zpbandflux('bessellb'))
def test_spectralmagsystem():
"""Check that SpectralMagSystem matches ABMagSystem when the spectrum is
the same as AB."""
# construct a spectrum with same flux as AB: 3631 x 10^{-23} erg/s/cm^2/Hz
wave = np.linspace(1000., 20000., 1000)
flux = 3631.e-23 * np.ones_like(wave)
unit = u.erg / u.s / u.cm**2 / u.Hz
s = sncosmo.Spectrum(wave, flux, unit=unit)
magsys1 = sncosmo.SpectralMagSystem(s)
magsys2 = sncosmo.ABMagSystem()
# Match is only good to 1e-3. Probably due to different methods
# of calculating bandflux between Spectrum and ABMagSystem.
assert_allclose(magsys1.zpbandflux('bessellb'),
magsys2.zpbandflux('bessellb'),
rtol=1e-3)
def test_abmagsystem():
magsys = sncosmo.ABMagSystem()
m = magsys.band_flux_to_mag(1.0, 'bessellb')
f = magsys.band_mag_to_flux(m, 'bessellb')
assert_almost_equal(f, 1.0)