Python Sed.fnu方法代码示例

# 需要导入模块: from lsst.sims.photUtils import Sed [as 别名]
# 或者: from lsst.sims.photUtils.Sed import fnu [as 别名]
    def _getSedCopy(self, sedName):
        """
        Return a copy of the requested SED, either from the cached
        version or creating a new one and caching a copy for later
        reuse.
        """
        if sedName in self.uniqueSeds:
            # we have already read in this file; no need to do it again
            sed = Sed(wavelen=self.uniqueSeds[sedName].wavelen,
                      flambda=self.uniqueSeds[sedName].flambda,
                      fnu=self.uniqueSeds[sedName].fnu,
                      name=self.uniqueSeds[sedName].name)
        else:
            # load the SED of the object
            sed = Sed()
            sedFile = os.path.join(self.sedDir, sedName)
            sed.readSED_flambda(sedFile)

            flambdaCopy = copy.deepcopy(sed.flambda)

            #If the SED is zero inside of the bandpass, GalSim raises an error.
            #This sets a minimum flux value of 1.0e-30 so that the SED is never technically
            #zero inside of the bandpass.
            sed.flambda = numpy.array([ff if ff>1.0e-30 else 1.0e-30 for ff in flambdaCopy])
            sed.fnu = None

            #copy the unnormalized file to uniqueSeds so we don't have to read it in again
            sedCopy = Sed(wavelen=sed.wavelen, flambda=sed.flambda,
                          fnu=sed.fnu, name=sed.name)
            self.uniqueSeds[sedName] = sedCopy
        return sed

# 需要导入模块: from lsst.sims.photUtils import Sed [as 别名]
# 或者: from lsst.sims.photUtils.Sed import fnu [as 别名]
    def _calculateGalSimSeds(self):
        """
        Apply any physical corrections to the objects' SEDS (redshift them, apply dust, etc.).
        Return a list of Sed objects containing the SEDS
        """

        sedList = []
        actualSEDnames = self.column_by_name('sedFilepath')
        redshift = self.column_by_name('redshift')
        internalAv = self.column_by_name('internalAv')
        internalRv = self.column_by_name('internalRv')
        galacticAv = self.column_by_name('galacticAv')
        galacticRv = self.column_by_name('galacticRv')
        magNorm = self.column_by_name('magNorm')

        #for setting magNorm
        imsimband = Bandpass()
        imsimband.imsimBandpass()

        outputNames=[]

        for (sedName, zz, iAv, iRv, gAv, gRv, norm) in \
            zip(actualSEDnames, redshift, internalAv, internalRv, galacticAv, galacticRv, magNorm):

            if is_null(sedName):
                sedList.append(None)
            else:
                if sedName in self.uniqueSeds:
                    #we have already read in this file; no need to do it again
                    sed = Sed(wavelen=self.uniqueSeds[sedName].wavelen,
                              flambda=self.uniqueSeds[sedName].flambda,
                              fnu=self.uniqueSeds[sedName].fnu,
                              name=self.uniqueSeds[sedName].name)
                else:
                    #load the SED of the object
                    sed = Sed()
                    sedFile = os.path.join(self.sedDir, sedName)
                    sed.readSED_flambda(sedFile)

                    flambdaCopy = copy.deepcopy(sed.flambda)

                    #If the SED is zero inside of the bandpass, GalSim raises an error.
                    #This sets a minimum flux value of 1.0e-30 so that the SED is never technically
                    #zero inside of the bandpass.
                    sed.flambda = numpy.array([ff if ff>1.0e-30 else 1.0e-30 for ff in flambdaCopy])
                    sed.fnu = None

                    #copy the unnormalized file to uniqueSeds so we don't have to read it in again
                    sedCopy = Sed(wavelen=sed.wavelen, flambda=sed.flambda,
                                  fnu=sed.fnu, name=sed.name)
                    self.uniqueSeds[sedName] = sedCopy

                #normalize the SED
                #Consulting the file sed.py in GalSim/galsim/ it appears that GalSim expects
                #its SEDs to ultimately be in units of ergs/nm so that, when called, they can
                #be converted to photons/nm (see the function __call__() and the assignment of
                #self._rest_photons in the __init__() of galsim's sed.py file).  Thus, we need
                #to read in our SEDs, normalize them, and then multiply by the exposure time
                #and the effective area to get from ergs/s/cm^2/nm to ergs/nm.
                #
                #The gain parameter should convert between photons and ADU (so: it is the
                #traditional definition of "gain" -- electrons per ADU -- multiplied by the
                #quantum efficiency of the detector).  Because we fold the quantum efficiency
                #of the detector into our total_[u,g,r,i,z,y].dat bandpass files
                #(see the readme in the THROUGHPUTS_DIR/baseline/), we only need to multiply
                #by the electrons per ADU gain.
                #
                #We will take these parameters from an instantiation of the PhotometricParameters
                #class (which can be reassigned by defining a daughter class of this class)
                #
                fNorm = sed.calcFluxNorm(norm, imsimband)
                sed.multiplyFluxNorm(fNorm)

                #apply dust extinction (internal)
                if iAv != 0.0 and iRv != 0.0:
                    a_int, b_int = sed.setupCCMab()
                    sed.addCCMDust(a_int, b_int, A_v=iAv, R_v=iRv)

                #22 June 2015
                #apply redshift; there is no need to apply the distance modulus from
                #sims/photUtils/CosmologyWrapper; magNorm takes that into account
                #however, magNorm does not take into account cosmological dimming
                if zz != 0.0:
                    sed.redshiftSED(zz, dimming=True)

                #apply dust extinction (galactic)
                a_int, b_int = sed.setupCCMab()
                sed.addCCMDust(a_int, b_int, A_v=gAv, R_v=gRv)
                sedList.append(sed)

        return sedList