def flux(self):
"""Return flux as flux density quantity"""
if qh.isMagnitude(self._flux):
tel = _valid_bands[self._bandname].lower()
return self._fsm.magtoflux(tel, self._bandname, self._flux)
else:
return self._flux
def error2(self):
"""Return error as flux density quantity (Isabelle's method)"""
if qh.isMagnitude(self._error):
#m_e = 2.5/ln(10) * F_e/F
#F_e = m_e*ln(10)/(F*2.5)
return self._error.value * self.flux * math.log(10) / 2.5
else:
return self._error
def __init__(self, bandname, flux, error, validity=1, unit=None):
"""Initialize a Photometry point.
Parameters:
bandname - string band name or constant, e.g. SLOAN
flux - the photometric value, astropy quantity with units of flux density or magnitude, or scalar if units provided
error - the photometric error, astropy quantity with units of flux density or magnitude, or scalar if units provided
validity - integer, 0=invalid, 1=valid, 2=lower limit, 3=upper limit
unit - astropy units of flux and error if they were given as a scalar
"""
if bandname not in _valid_bands:
warnings.warn(
"Unrecognized band name %s. Will not be able to convert between flux density and magnitude."
% bandname)
self._bandname = bandname
if qh.isFluxDensity(flux) or qh.isMagnitude(flux):
self._flux = flux
else:
if unit == None:
raise Exception(
"flux or unit must be a Magnitude or Flux Density Quantity"
)
else:
self._flux = flux * unit
if qh.isFluxDensity(error) or qh.isMagnitude(error):
self._error = error
else:
if unit == None:
raise Exception(
"error must be a Magnitude or Flux Density Quantity")
else:
self._error = error * unit
if not (
(qh.isFluxDensity(self._flux) and qh.isFluxDensity(self._error)) or
(qh.isMagnitude(self._flux) and qh.isMagnitude(self._error))):
raise Exception(
"flux and error must be a Magnitude or Flux Density Quantity and have equivalent units"
)
self._validity = validity
self._fsm = FilterSetManager()
def errormjy(self):
"""Return the error in millijanskies as a scalar"""
# S/N is the fractional error on the *flux*
# NtoS is 1/(S/N)
# error(mag) =
if qh.isMagnitude(self._error):
NtoS = 10.0**(self._error.value / 2.5) - 1.0
_errormjy = self.mjy * NtoS
#t1 = -2.5*math.log10(math.e)/fluxmjy.value
#errormjy1 = math.fabs(self._error.value*t1)
#print("tel %s, band %s, error %s, NtoS %s t1 %s fluxmjy %s errormjy %s e1 %s"%(tel,self._bandname,self._error, NtoS, t1, fluxmjy,errormjy,errormjy1))
return _errormjy
else:
return self._error.to(u.mJy).value
def error3(self):
"""Return error as flux density quantity (sanity check)"""
if qh.isMagnitude(self._error):
#m_e = 2.5/ln(10) * F_e/F
#F_e = m_e*ln(10)/(F*2.5)
valuep = self._flux + self._error
valuem = self._flux - self._error
#print("V ",valuep,valuem)
tel = _valid_bands[self._bandname].lower()
fp = self._fsm.magtoflux(tel, self._bandname, valuep)
fm = self._fsm.magtoflux(tel, self._bandname, valuem)
return fp.unit * (fm.value - fp.value) / 2.0
else:
return self._error
def magtoflux(self, telescope, band, magnitude, mjy=True):
"""Return the flux density in Jansky or milliJansky of a source as an astropy Quantity,
given the source magnitude.
Parameters:
telescope - string or (string constant) telescope name, e.g.
SLOAN, 'gaia', '2MASS', 'Spitzer', HERSCHEL, WISE
band - wave band name of telescope e.g., 'u' or SDSS_u for Sloan, IRAC1 or 'I1' for spitzer
magnitude - magnitude of source, as scalar or astropy magnitude Quantity
mjy - boolean to return flux in mJy. True returns mJy, False returns Jy. Default:True
Example: magtoflux(SLOAN,SDSS_u,10) returns 156.85 mJy
"""
zpjy = self._filtersets[telescope.lower()][band].zp().to(u.Jy)
#print("TBM: %s %s %s %s"%(telescope,band,magnitude,zpjy))
if qh.isMagnitude(magnitude):
value = zpjy * 10.0**(magnitude.value / -2.5)
else:
value = zpjy * 10.0**(magnitude / -2.5)
if mjy == True:
return value.to(u.mJy)
else:
return value.to(Jy)
dec=-22 * u.degree)
# will raise exception
try:
pm = SED("testbaddistance", 100 * u.degree, 13.3 * u.hour,
-22 * u.degree)
except Exception as e:
print("EXCEPTION CAUGHT:", e)
q = 1 * u.Jy
#source id 4885742854871204860
pm.addData(fm.SDSS_z,
u.Magnitude(14.15327),
u.Magnitude(0.007049335),
validity=1)
pm.addData(fm.SDSS_i,
u.Magnitude(14.29342),
u.Magnitude(0.006180155),
validity=1)
#pm.addData(fm.TWOMASS_K,q, q/100.0,validity=1)
print(pm.errors())
print(pm.errors().to(u.uJy))
if False:
# will raise warning
pm.addData("3J", q / 10, q / 300.0, 1)
pm.addData(fm.SDSS_u, q / 100, q / 1000.0, 0)
print(pm.sedfitterinput())
g = u.Magnitude(10)
print(g)
print(g.unit)
print(qh.isMagnitude(g))
def error(self):
"""Return error as flux density quantity (Marc's method)"""
if qh.isMagnitude(self._error):
return self.errormjy * u.mJy
else:
return self._error