Source code for pyuvdata.calfits

# -*- mode: python; coding: utf-8 -*-
# Copyright (c) 2018 Radio Astronomy Software Group
# Licensed under the 2-clause BSD License

from __future__ import absolute_import, division, print_function

import numpy as np
import warnings
from astropy.io import fits

from . import UVCal
from . import utils as uvutils


def _warn_oldcalfits(filename):
    warnings.warn('{file} appears to be an old calfits format '
                  'which does not fully conform to the FITS standard. '
                  'Setting default values now, set strict_fits=True '
                  'to error rather than warn on this problem, '
                  'rewrite this file with write_calfits to ensure '
                  'FITS compliance. Support for this file will '
                  'go away in version 1.5'.format(file=filename),
                  DeprecationWarning)


def _warn_olddelay(filename):
    warnings.warn('{file} appears to be an old calfits format '
                  'for delay files which has been deprecated. '
                  'Rewrite this file with write_calfits to ensure '
                  'future compatibility. Support for this file will '
                  'go away in version 1.5'.format(file=filename),
                  DeprecationWarning)


def _warn_oldstyle(filename):
    warnings.warn('{file} appears to be an old calfits format '
                  'which has been deprecated. '
                  'Rewrite this file with write_calfits to ensure '
                  'future compatibility. Support for this file will '
                  'go away in version 1.5'.format(file=filename),
                  DeprecationWarning)


[docs]class CALFITS(UVCal): """ Defines a calfits-specific class for reading and writing calfits files. """
[docs] def write_calfits(self, filename, run_check=True, check_extra=True, run_check_acceptability=True, clobber=False): """ Write the data to a calfits file. Args: filename: The calfits file to write to. run_check: Option to check for the existence and proper shapes of parameters before writing the file. Default is True. check_extra: Option to check optional parameters as well as required ones. Default is True. run_check_acceptability: Option to check acceptable range of the values of parameters before writing the file. Default is True. clobber: Option to overwrite the filename if the file already exists. Default is False. """ if run_check: self.check(check_extra=check_extra, run_check_acceptability=run_check_acceptability) if self.Nfreqs > 1: freq_spacing = self.freq_array[0, 1:] - self.freq_array[0, :-1] if not np.isclose(np.min(freq_spacing), np.max(freq_spacing), rtol=self._freq_array.tols[0], atol=self._freq_array.tols[1]): raise ValueError('The frequencies are not evenly spaced (probably ' 'because of a select operation). The calfits format ' 'does not support unevenly spaced frequencies.') if np.isclose(freq_spacing[0], self.channel_width): freq_spacing = self.channel_width else: rounded_spacing = np.around(freq_spacing, int(np.ceil(np.log10(self._freq_array.tols[1]) * -1))) freq_spacing = rounded_spacing[0] else: freq_spacing = self.channel_width if self.Ntimes > 1: time_spacing = np.diff(self.time_array) if not np.isclose(np.min(time_spacing), np.max(time_spacing), rtol=self._time_array.tols[0], atol=self._time_array.tols[1]): raise ValueError('The times are not evenly spaced (probably ' 'because of a select operation). The calfits format ' 'does not support unevenly spaced times.') if np.isclose(time_spacing[0], self.integration_time / (24. * 60.**2)): time_spacing = self.integration_time / (24. * 60.**2) else: rounded_spacing = np.around(time_spacing, int(np.ceil(np.log10(self._time_array.tols[1] / self.Ntimes) * -1) + 1)) time_spacing = rounded_spacing[0] else: time_spacing = self.integration_time / (24. * 60.**2) if self.Njones > 1: jones_spacing = np.diff(self.jones_array) if np.min(jones_spacing) < np.max(jones_spacing): raise ValueError('The jones values are not evenly spaced.' 'The calibration fits file format does not' ' support unevenly spaced polarizations.') jones_spacing = jones_spacing[0] else: jones_spacing = -1 prihdr = fits.Header() if self.total_quality_array is not None: totqualhdr = fits.Header() totqualhdr['EXTNAME'] = 'TOTQLTY' if self.cal_type != 'gain': sechdr = fits.Header() sechdr['EXTNAME'] = 'FLAGS' # Conforming to fits format prihdr['SIMPLE'] = True prihdr['BITPIX'] = 32 prihdr['TELESCOP'] = self.telescope_name prihdr['GNCONVEN'] = self.gain_convention prihdr['CALTYPE'] = self.cal_type prihdr['CALSTYLE'] = self.cal_style if self.sky_field is not None: prihdr['FIELD'] = self.sky_field if self.sky_catalog is not None: prihdr['CATALOG'] = self.sky_catalog if self.ref_antenna_name is not None: prihdr['REFANT'] = self.ref_antenna_name if self.Nsources is not None: prihdr['NSOURCES'] = self.Nsources if self.baseline_range is not None: prihdr['BL_RANGE'] = '[' + ', '.join([str(b) for b in self.baseline_range]) + ']' if self.diffuse_model is not None: prihdr['DIFFUSE'] = self.diffuse_model prihdr['INTTIME'] = self.integration_time prihdr['CHWIDTH'] = self.channel_width prihdr['XORIENT'] = self.x_orientation if self.cal_type == 'delay': prihdr['FRQRANGE'] = ','.join(map(str, self.freq_range)) elif self.freq_range is not None: prihdr['FRQRANGE'] = ','.join(map(str, self.freq_range)) prihdr['TMERANGE'] = ','.join(map(str, self.time_range)) if self.observer: prihdr['OBSERVER'] = self.observer if self.git_origin_cal: prihdr['ORIGCAL'] = self.git_origin_cal if self.git_hash_cal: prihdr['HASHCAL'] = self.git_hash_cal if self.cal_type == 'unknown': raise ValueError("unknown calibration type. Do not know how to " "store parameters") # Define primary header values # Arrays have (column-major) dimensions of [Nimages, Njones, Ntimes, Nfreqs, Nspw, Nantennas] # For a "delay"-type calibration, Nfreqs is a shallow axis # set the axis for number of arrays prihdr['CTYPE1'] = ('Narrays', 'Number of image arrays.') prihdr['CUNIT1'] = 'Integer' prihdr['CDELT1'] = 1 prihdr['CRPIX1'] = 1 prihdr['CRVAL1'] = 1 # Jones axis prihdr['CTYPE2'] = ('JONES', 'Jones matrix array') prihdr['CUNIT2'] = ('Integer', 'representative integer for polarization.') prihdr['CRPIX2'] = 1 prihdr['CRVAL2'] = self.jones_array[0] # always start with first jones. prihdr['CDELT2'] = jones_spacing # time axis prihdr['CTYPE3'] = ('TIME', 'Time axis.') prihdr['CUNIT3'] = ('JD', 'Time in julian date format') prihdr['CRPIX3'] = 1 prihdr['CRVAL3'] = self.time_array[0] prihdr['CDELT3'] = time_spacing # freq axis prihdr['CTYPE4'] = ('FREQS', 'Frequency.') prihdr['CUNIT4'] = 'Hz' prihdr['CRPIX4'] = 1 prihdr['CRVAL4'] = self.freq_array[0][0] prihdr['CDELT4'] = freq_spacing # spw axis: number of spectral windows prihdr['CTYPE5'] = ('IF', 'Spectral window number.') prihdr['CUNIT5'] = 'Integer' prihdr['CRPIX5'] = 1 prihdr['CRVAL5'] = 1 prihdr['CDELT5'] = 1 # antenna axis prihdr['CTYPE6'] = ('ANTAXIS', 'See ANTARR in ANTENNA extension for values.') prihdr['CUNIT6'] = 'Integer' prihdr['CRPIX6'] = 1 prihdr['CRVAL6'] = 1 prihdr['CDELT6'] = -1 # end standard keywords; begin user-defined keywords for key, value in self.extra_keywords.items(): # header keywords have to be 8 characters or less if len(str(key)) > 8: warnings.warn('key {key} in extra_keywords is longer than 8 ' 'characters. It will be truncated to 8 as required ' 'by the calfits file format.'.format(key=key)) keyword = key[:8].upper() if isinstance(value, (dict, list, np.ndarray)): raise TypeError('Extra keyword {keyword} is of {keytype}. ' 'Only strings and numbers are ' 'supported in calfits.'.format(keyword=key, keytype=type(value))) if keyword == 'COMMENT': for line in value.splitlines(): prihdr.add_comment(line) else: prihdr[keyword] = value for line in self.history.splitlines(): prihdr.add_history(line) # define data section based on calibration type if self.cal_type == 'gain': if self.input_flag_array is not None: pridata = np.concatenate([self.gain_array.real[:, :, :, :, :, np.newaxis], self.gain_array.imag[:, :, :, :, :, np.newaxis], self.flag_array[:, :, :, :, :, np.newaxis], self.input_flag_array[:, :, :, :, :, np.newaxis], self.quality_array[:, :, :, :, :, np.newaxis]], axis=-1) else: pridata = np.concatenate([self.gain_array.real[:, :, :, :, :, np.newaxis], self.gain_array.imag[:, :, :, :, :, np.newaxis], self.flag_array[:, :, :, :, :, np.newaxis], self.quality_array[:, :, :, :, :, np.newaxis]], axis=-1) elif self.cal_type == 'delay': pridata = np.concatenate([self.delay_array[:, :, :, :, :, np.newaxis], self.quality_array[:, :, :, :, :, np.newaxis]], axis=-1) # Set headers for the second hdu containing the flags. Only in cal_type=delay # Can't put in pridata because frequency axis is shallow there, but not here # Header values are the same as the primary header sechdr['CTYPE1'] = ('Narrays', 'Number of image arrays.') sechdr['CUNIT1'] = 'Integer' sechdr['CRPIX1'] = 1 sechdr['CRVAL1'] = 1 sechdr['CDELT1'] = 1 sechdr['CTYPE2'] = ('JONES', 'Jones matrix array') sechdr['CUNIT2'] = ('Integer', 'representative integer for polarization.') sechdr['CRPIX2'] = 1 sechdr['CRVAL2'] = self.jones_array[0] # always start with first jones. sechdr['CDELT2'] = jones_spacing sechdr['CTYPE3'] = ('TIME', 'Time axis.') sechdr['CUNIT3'] = ('JD', 'Time in julian date format') sechdr['CRPIX3'] = 1 sechdr['CRVAL3'] = self.time_array[0] sechdr['CDELT3'] = time_spacing sechdr['CTYPE4'] = ('FREQS', 'Valid frequencies to apply delay.') sechdr['CUNIT4'] = 'Hz' sechdr['CRPIX4'] = 1 sechdr['CRVAL4'] = self.freq_array[0][0] sechdr['CDELT4'] = freq_spacing sechdr['CTYPE5'] = ('IF', 'Spectral window number.') sechdr['CUNIT5'] = 'Integer' sechdr['CRPIX5'] = 1 sechdr['CRVAL5'] = 1 sechdr['CDELT5'] = 1 sechdr['CTYPE6'] = ('ANTAXIS', 'See ANTARR in ANTENNA extension for values.') # convert from bool to int64; undone on read if self.input_flag_array is not None: secdata = np.concatenate([self.flag_array.astype(np.int64)[:, :, :, :, :, np.newaxis], self.input_flag_array.astype(np.int64)[:, :, :, :, :, np.newaxis]], axis=-1) else: secdata = self.flag_array.astype(np.int64)[:, :, :, :, :, np.newaxis] if self.total_quality_array is not None: # Set headers for the hdu containing the total_quality_array # No antenna axis, so we have [Njones, Ntime, Nfreq, Nspws] totqualhdr['CTYPE1'] = ('JONES', 'Jones matrix array') totqualhdr['CUNIT1'] = ('Integer', 'representative integer for polarization.') totqualhdr['CRPIX1'] = 1 totqualhdr['CRVAL1'] = self.jones_array[0] # always start with first jones. totqualhdr['CDELT1'] = jones_spacing totqualhdr['CTYPE2'] = ('TIME', 'Time axis.') totqualhdr['CUNIT2'] = ('JD', 'Time in julian date format') totqualhdr['CRPIX2'] = 1 totqualhdr['CRVAL2'] = self.time_array[0] totqualhdr['CDELT2'] = time_spacing totqualhdr['CTYPE3'] = ('FREQS', 'Valid frequencies to apply delay.') totqualhdr['CUNIT3'] = 'Hz' totqualhdr['CRPIX3'] = 1 totqualhdr['CRVAL3'] = self.freq_array[0][0] totqualhdr['CDELT3'] = freq_spacing # spws axis: number of spectral windows totqualhdr['CTYPE4'] = ('IF', 'Spectral window number.') totqualhdr['CUNIT4'] = 'Integer' totqualhdr['CRPIX4'] = 1 totqualhdr['CRVAL4'] = 1 totqualhdr['CDELT4'] = 1 totqualdata = self.total_quality_array # make HDUs prihdu = fits.PrimaryHDU(data=pridata, header=prihdr) # ant HDU col1 = fits.Column(name='ANTNAME', format='8A', array=self.antenna_names) col2 = fits.Column(name='ANTINDEX', format='D', array=self.antenna_numbers) if self.Nants_data == self.Nants_telescope: col3 = fits.Column(name='ANTARR', format='D', array=self.ant_array) else: # ant_array is shorter than the other columns. # Pad the extra rows with -1s. Need to undo on read. nants_add = self.Nants_telescope - self.Nants_data ant_array_use = np.append(self.ant_array, np.zeros(nants_add, dtype=np.int) - 1) col3 = fits.Column(name='ANTARR', format='D', array=ant_array_use) cols = fits.ColDefs([col1, col2, col3]) ant_hdu = fits.BinTableHDU.from_columns(cols) ant_hdu.header['EXTNAME'] = 'ANTENNAS' hdulist = fits.HDUList([prihdu, ant_hdu]) if self.cal_type != 'gain': sechdu = fits.ImageHDU(data=secdata, header=sechdr) hdulist.append(sechdu) if self.total_quality_array is not None: totqualhdu = fits.ImageHDU(data=totqualdata, header=totqualhdr) hdulist.append(totqualhdu) hdulist.writeto(filename, overwrite=clobber)
[docs] def read_calfits(self, filename, run_check=True, check_extra=True, run_check_acceptability=True, strict_fits=False): """ Read data from a calfits file. Args: filename: The calfits file to read to. run_check: Option to check for the existence and proper shapes of parameters after reading in the file. Default is True. check_extra: Option to check optional parameters as well as required ones. Default is True. run_check_acceptability: Option to check acceptable range of the values of parameters after reading in the file. Default is True. strict_fits: boolean If True, require that the data axes have cooresponding NAXIS, CRVAL, CDELT and CRPIX keywords. If False, allow CRPIX to be missing and set it equal to zero and allow the CRVAL for the spw directions to be missing and set it to zero. This keyword exists to support old calfits files that were missing many CRPIX and CRVAL keywords. Default is False. """ with fits.open(filename) as F: data = F[0].data hdr = F[0].header.copy() hdunames = uvutils._fits_indexhdus(F) anthdu = F[hdunames['ANTENNAS']] self.Nants_telescope = anthdu.header['NAXIS2'] antdata = anthdu.data self.antenna_names = np.array(list(map(str, antdata['ANTNAME']))) self.antenna_numbers = np.array(list(map(int, antdata['ANTINDEX']))) self.ant_array = np.array(list(map(int, antdata['ANTARR']))) if np.min(self.ant_array) < 0: # ant_array was shorter than the other columns, so it was padded with -1s. # Remove the padded entries. self.ant_array = self.ant_array[np.where(self.ant_array >= 0)[0]] self.channel_width = hdr.pop('CHWIDTH') self.integration_time = hdr.pop('INTTIME') self.telescope_name = hdr.pop('TELESCOP') self.history = str(hdr.get('HISTORY', '')) if not uvutils._check_history_version(self.history, self.pyuvdata_version_str): if not self.history.endswith('\n'): self.history += '\n' self.history += self.pyuvdata_version_str while 'HISTORY' in hdr.keys(): hdr.remove('HISTORY') self.time_range = list(map(float, hdr.pop('TMERANGE').split(','))) self.gain_convention = hdr.pop('GNCONVEN') self.x_orientation = hdr.pop('XORIENT') self.cal_type = hdr.pop('CALTYPE') if self.cal_type == 'delay': self.freq_range = list(map(float, hdr.pop('FRQRANGE').split(','))) else: if 'FRQRANGE' in hdr: self.freq_range = list(map(float, hdr.pop('FRQRANGE').split(','))) if 'CALSTYLE' not in hdr: _warn_oldstyle(filename) self.cal_style = 'redundant' else: self.cal_style = hdr.pop('CALSTYLE') self.sky_field = hdr.pop('FIELD', None) self.sky_catalog = hdr.pop('CATALOG', None) self.ref_antenna_name = hdr.pop('REFANT', None) self.Nsources = hdr.pop('NSOURCES', None) bl_range_string = hdr.pop('BL_RANGE', None) if bl_range_string is not None: self.baseline_range = [float(b) for b in bl_range_string.strip('[').strip(']').split(',')] self.diffuse_model = hdr.pop('DIFFUSE', None) self.observer = hdr.pop('OBSERVER', None) self.git_origin_cal = hdr.pop('ORIGCAL', None) self.git_hash_cal = hdr.pop('HASHCAL', None) # generate polarization and time array for either cal_type. self.Njones = hdr.pop('NAXIS2') self.jones_array = uvutils._fits_gethduaxis(F[0], 2, strict_fits=strict_fits) self.Ntimes = hdr.pop('NAXIS3') self.time_array = uvutils._fits_gethduaxis(F[0], 3, strict_fits=strict_fits) # get data. if self.cal_type == 'gain': self.set_gain() self.gain_array = data[:, :, :, :, :, 0] + 1j * data[:, :, :, :, :, 1] self.flag_array = data[:, :, :, :, :, 2].astype('bool') if hdr.pop('NAXIS1') == 5: self.input_flag_array = data[:, :, :, :, :, 3].astype('bool') self.quality_array = data[:, :, :, :, :, 4] else: self.quality_array = data[:, :, :, :, :, 3] self.Nants_data = hdr.pop('NAXIS6') self.Nspws = hdr.pop('NAXIS5') # add this for backwards compatibility when the spw CRVAL wasn't recorded try: spw_array = uvutils._fits_gethduaxis(F[0], 5, strict_fits=strict_fits) if spw_array[0] == 0: # XXX: backwards compatibility: if array is already (erroneously) zero- # indexed, do nothing self.spw_array = spw_array else: # subtract 1 to be zero-indexed self.spw_array = uvutils._fits_gethduaxis(F[0], 5, strict_fits=strict_fits) - 1 except(KeyError): if not strict_fits: _warn_oldcalfits(filename) self.spw_array = np.array([0]) else: raise # generate frequency array from primary data unit. self.Nfreqs = hdr.pop('NAXIS4') self.freq_array = uvutils._fits_gethduaxis(F[0], 4, strict_fits=strict_fits) self.freq_array.shape = (self.Nspws,) + self.freq_array.shape if self.cal_type == 'delay': self.set_delay() try: # delay-style should have the same number of axes as gains self.Nants_data = hdr.pop('NAXIS6') self.Nspws = hdr.pop('NAXIS5') ax_spw = 5 old_delay = False except(KeyError): _warn_olddelay(filename) self.Nants_data = hdr.pop('NAXIS5') self.Nspws = hdr.pop('NAXIS4') ax_spw = 4 old_delay = True if old_delay: self.delay_array = data[:, :, np.newaxis, :, :, 0] self.quality_array = data[:, :, np.newaxis, :, :, 1] else: self.delay_array = data[:, :, :, :, :, 0] self.quality_array = data[:, :, :, :, :, 1] sechdu = F[hdunames['FLAGS']] flag_data = sechdu.data flag_hdr = sechdu.header if sechdu.header['NAXIS1'] == 2: self.flag_array = flag_data[:, :, :, :, :, 0].astype('bool') self.input_flag_array = flag_data[:, :, :, :, :, 1].astype('bool') else: self.flag_array = flag_data[:, :, :, :, :, 0].astype('bool') # add this for backwards compatibility when the spw CRVAL wasn't recorded try: spw_array = uvutils._fits_gethduaxis(F[0], ax_spw, strict_fits=strict_fits) if spw_array[0] == 0: # XXX: backwards compatibility: if array is already (erroneously) zero- # indexed, do nothing self.spw_array = spw_array else: # subtract 1 to be zero-indexed self.spw_array = spw_array - 1 except(KeyError): if not strict_fits: _warn_oldcalfits(filename) self.spw_array = np.array([0]) else: raise # generate frequency array from flag data unit (no freq axis in primary). self.Nfreqs = sechdu.header['NAXIS4'] self.freq_array = uvutils._fits_gethduaxis(sechdu, 4, strict_fits=strict_fits) self.freq_array.shape = (self.Nspws,) + self.freq_array.shape # add this for backwards compatibility when the spw CRVAL wasn't recorded try: spw_array = uvutils._fits_gethduaxis(sechdu, 5, strict_fits=strict_fits) - 1 except(KeyError): if not strict_fits: _warn_oldcalfits(filename) spw_array = np.array([0]) else: raise if not np.allclose(spw_array, self.spw_array): raise ValueError('Spectral window values are different in FLAGS HDU than in primary HDU') time_array = uvutils._fits_gethduaxis(sechdu, 3, strict_fits=strict_fits) if not np.allclose(time_array, self.time_array, rtol=self._time_array.tols[0], atol=self._time_array.tols[0]): raise ValueError('Time values are different in FLAGS HDU than in primary HDU') jones_array = uvutils._fits_gethduaxis(sechdu, 2, strict_fits=strict_fits) if not np.allclose(jones_array, self.jones_array, rtol=self._jones_array.tols[0], atol=self._jones_array.tols[0]): raise ValueError('Jones values are different in FLAGS HDU than in primary HDU') # remove standard FITS header items that are still around std_fits_substrings = ['SIMPLE', 'BITPIX', 'EXTEND', 'BLOCKED', 'GROUPS', 'PCOUNT', 'BSCALE', 'BZERO', 'NAXIS', 'PTYPE', 'PSCAL', 'PZERO', 'CTYPE', 'CRVAL', 'CRPIX', 'CDELT', 'CROTA', 'CUNIT'] for key in list(hdr.keys()): for sub in std_fits_substrings: if key.find(sub) > -1: hdr.remove(key) # find all the remaining header items and keep them as extra_keywords for key in hdr: if key == 'COMMENT': self.extra_keywords[key] = str(hdr.get(key)) elif key != '': self.extra_keywords[key] = hdr.get(key) # get total quality array if present if 'TOTQLTY' in hdunames: totqualhdu = F[hdunames['TOTQLTY']] self.total_quality_array = totqualhdu.data # add this for backwards compatibility when the spw CRVAL wasn't recorded try: spw_array = uvutils._fits_gethduaxis(totqualhdu, 4, strict_fits=strict_fits) - 1 except(KeyError): if not strict_fits: _warn_oldcalfits(filename) spw_array = np.array([0]) else: raise if not np.allclose(spw_array, self.spw_array): raise ValueError('Spectral window values are different in ' 'TOTQLTY HDU than in primary HDU. primary HDU ' 'has {pspw}, TOTQLTY has {tspw}' .format(pspw=self.spw_array, tspw=spw_array)) if self.cal_type != 'delay': # delay-type files won't have a freq_array freq_array = uvutils._fits_gethduaxis(totqualhdu, 3, strict_fits=strict_fits) freq_array.shape = (self.Nspws,) + freq_array.shape if not np.allclose(freq_array, self.freq_array, rtol=self._freq_array.tols[0], atol=self._freq_array.tols[0]): raise ValueError('Frequency values are different in TOTQLTY HDU than in primary HDU') time_array = uvutils._fits_gethduaxis(totqualhdu, 2, strict_fits=strict_fits) if not np.allclose(time_array, self.time_array, rtol=self._time_array.tols[0], atol=self._time_array.tols[0]): raise ValueError('Time values are different in TOTQLTY HDU than in primary HDU') jones_array = uvutils._fits_gethduaxis(totqualhdu, 1, strict_fits=strict_fits) if not np.allclose(jones_array, self.jones_array, rtol=self._jones_array.tols[0], atol=self._jones_array.tols[0]): raise ValueError('Jones values are different in TOTQLTY HDU than in primary HDU') else: self.total_quality_array = None if run_check: self.check(check_extra=check_extra, run_check_acceptability=run_check_acceptability)