transmissionCurve.py

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# This file is part of ip_isr.
#
# Developed for the LSST Data Management System.
# This product includes software developed by the LSST Project
# (https://www.lsst.org).
# See the COPYRIGHT file at the top-level directory of this distribution
# for details of code ownership.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
__all__ = ["IntermediateTransmissionCurve",
           "IntermediateOpticsTransmissionCurve",
           "IntermediateFilterTransmissionCurve",
           "IntermediateFilterDetectorTransmissionCurve",
           "IntermediateSensorTransmissionCurve",
           "IntermediateAtmosphereTransmissionCurve",
           "IntermediateSystemTransmissionCurve", ]
 
import numpy as np
from astropy import units as u
from astropy.units import cds
 
from lsst.afw.image import TransmissionCurve
from .calibType import IsrCalib
 
 
class IntermediateTransmissionCurve(IsrCalib):
    """Definition for the TransmissionCurve format used as inputs.
 
    Parameters
    ----------
    filename : `str`
        Filename of a transmission curve dataset.
    """
 
    _OBSTYPE = "transmission_curve"
    _SCHEMA = ""
    _VERSION = 1.0
 
    def __init__(self, filename=None):
        self.data = None
        self.transmissionCurve = None
        self.isSpatiallyConstant = True
        super().__init__()
 
        # Because we are not persisting this calib as itself, we
        # should skip adding any other attributes.
        self.requiredAttributes.update(['isSpatiallyConstant'])
 
    def setMetadata(self, metadata):
        # Inherits from lsst.ip.isr.IsrCalib.setMetadata.
        super().setMetadata(metadata)
 
    @classmethod
    def fromTable(cls, tableList):
        """Construct intermediate transmission curve from a list of input
        tables.  Only the first table is used.
 
        Parameters
        ----------
        tableList : `list` [`astropy.table.Table`]
            List containing input tables.
 
        Returns
        -------
        calib : `lsst.ip.isr.IntermediateTransmissionCurve`
            The final calibration.
        """
        calib = cls()
 
        metadata = tableList[0].meta
        calib.setMetadata(metadata)
        calib.updateMetadata()
 
        calib.data = tableList[0]
        calib.setTransmissionCurveRepresentation()
        return calib
 
    def setTransmissionCurveRepresentation(self):
        """Construct transmission curve representation from the data that was
        read.
 
        Raises
        ------
        RuntimeError
            This is raised if no table data exists in the calibration,
            if there are array length mismatches, or if the wavelength
            sampling for multi-amp tables differ.
        """
        if self.data is None:
            raise RuntimeError("No table data was found to convert to a transmission curve!")
 
        throughputKey = None
        if 'wavelength' not in self.data.columns:
            raise RuntimeError("Expected column [wavelength] not found.")
        if 'efficiency' in self.data.columns:
            throughputKey = 'efficiency'
        elif 'throughput' in self.data.columns:
            throughputKey = 'throughput'
        else:
            raise RuntimeError("Expected columns [throughput|efficiency] not found.")
 
        doAverageCurves = False
        if 'amp_name' in self.data.columns:
            doAverageCurves = True
 
        # These will be used to construct the
        # ``lsst.afw.image.TransmissionCurve`` object.
        wavelengths = None
        throughput = None
 
        if doAverageCurves:
            curveStack = None
            amplifierNames = set(self.data['amp_name'])
            comparisonIndices = np.where(self.data['amp_name'] == next(iter(amplifierNames)))
            wavelengths = self.data[comparisonIndices]['wavelength']
 
            for amplifier in amplifierNames:
                indices = np.where(self.data['amp_name'] == amplifier)
                if len(self.data[indices]) != len(self.data[comparisonIndices]):
                    raise RuntimeError("Incompatible lengths in average.")
                if not np.array_equal(self.data[indices]['wavelength'], wavelengths):
                    raise RuntimeError("Mismatch in wavelength samples.")
 
                if curveStack is not None:
                    curveStack = np.column_stack((curveStack, self.data[indices][throughputKey]))
                else:
                    curveStack = self.data[indices][throughputKey]
            throughput = np.mean(curveStack, 1)
 
            # This averaging operation has stripped units.
            throughput = throughput * self.data[throughputKey].unit
        else:
            wavelengths = self.data['wavelength']
            throughput = self.data[throughputKey]
 
        # Convert units:
        # import pdb; pdb.set_trace()
        with cds.enable():
            # These need to be in Angstroms, for consistency.
            wavelengths = wavelengths.to(u.Angstrom).to_value()
 
            if throughput.unit != u.dimensionless_unscaled and throughput.unit != u.UnrecognizedUnit('-'):
                # These need to be fractions, not percent.
                throughput = throughput.to(u.dimensionless_unscaled).to_value()
 
        self.transmissionCurve = TransmissionCurve.makeSpatiallyConstant(
            throughput.astype(np.float64),
            wavelengths.astype(np.float64),
            throughputAtMin=0.0,
            throughputAtMax=0.0
        )
 
    def getTransmissionCurve(self):
        if self.transmissionCurve is None and self.data is None:
            raise RuntimeError("No transmission curve data found.")
        if self.transmissionCurve is None:
            self.setTransmissionCurveRepresentation()
        return self.transmissionCurve
 
    def writeFits(self, outputFilename):
        """Write the transmission curve data to a file.
 
        Parameters
        ----------
        outputFilename : `str`
            Destination filename.
 
        Returns
        -------
        outputFilename : `str`
            The output filename actually used.
 
        Raises
        ------
        RuntimeError
            Raised if no transmission curve can be created.
        """
        if self.transmissionCurve is None and self.data is None:
            raise RuntimeError("No transmission curve data found.")
        if self.transmissionCurve is None:
            self.setTransmissionCurveRepresentation()
 
        return self.transmissionCurve.writeFits(outputFilename)
 
 
class IntermediateSensorTransmissionCurve(IntermediateTransmissionCurve):
    _OBSTYPE = 'transmission_sensor'
 
 
class IntermediateFilterTransmissionCurve(IntermediateTransmissionCurve):
    _OBSTYPE = 'transmission_filter'
 
 
class IntermediateFilterDetectorTransmissionCurve(IntermediateTransmissionCurve):
    _OBSTYPE = 'transmission_filter_detector'
 
 
class IntermediateOpticsTransmissionCurve(IntermediateTransmissionCurve):
    _OBSTYPE = 'transmission_optics'
 
 
class IntermediateAtmosphereTransmissionCurve(IntermediateTransmissionCurve):
    _OBSTYPE = 'transmission_atmosphere'
 
 
class IntermediateSystemTransmissionCurve(IntermediateTransmissionCurve):
    _OBSTYPE = 'transmission_system'