def is_daytime(self, key, csd):
src = self[key] if isinstance(key, basestring) else key
is_daytime = 0
src_ra, src_dec = ephemeris.object_coords(src.body, date=ephemeris.csd_to_unix(csd), deg=True)
transit_start = ephemeris.csd_to_unix(csd + (src_ra - src.window) / 360.0)
transit_end = ephemeris.csd_to_unix(csd + (src_ra + src.window) / 360.0)
solar_rise = ephemeris.solar_rising(transit_start - 24.0*3600.0, end_time=transit_end)
for rr in solar_rise:
ss = ephemeris.solar_setting(rr)[0]
rrex = rr + self._extend_night
ssex = ss - self._extend_night
if ((transit_start <= ssex) and (rrex <= transit_end)):
is_daytime += 1
tt = ephemeris.solar_transit(rr)[0]
if (transit_start <= tt) and (tt <= transit_end):
is_daytime += 1
break
return is_daytime
def add_file(self, filename):
# Make sure this file is not currently in the transit tracker
if self.contains_file(filename):
return
# Read file time range
with h5py.File(filename, 'r') as handler:
timestamp = handler['index_map']['time']['ctime'][:]
timestamp0 = np.median(timestamp)
# Convert to right ascension
ra = ephemeris.lsa(timestamp)
csd = ephemeris.csd(timestamp)
# Loop over available sources
for name, src in self.iteritems():
src_ra, src_dec = ephemeris.object_coords(src.body,
date=timestamp0,
deg=True)
src_ra = (src_ra + src.shift) % 360.0
# Determine if any times in this file fall
# in a window around transit of this source
hour_angle = ra - src_ra
hour_angle = hour_angle + 360.0 * (hour_angle < -180.0) - 360.0 * (
hour_angle > 180.0)
good_time = np.flatnonzero(np.abs(hour_angle) < src.window)
if good_time.size > 0:
# Determine the csd for the transit contained in this file
icsd = np.unique(
np.floor(csd[good_time] - (hour_angle[good_time] / 360.0)))
if icsd.size > 1:
RuntimeError("Error estimating CSD.")
key = int(icsd[0])
min_ha, max_ha = np.percentile(hour_angle, [0, 100])
# Add to list of files to analyze for this source
if key in src.files:
src.files[key].append((filename, hour_angle))
src.file_span[key][0] = min(min_ha, src.file_span[key][0])
src.file_span[key][1] = max(max_ha, src.file_span[key][1])
else:
src.files[key] = [(filename, hour_angle)]
src.file_span[key] = [min_ha, max_ha]
def _finalize_transit(self):
"""Concatenate grouped time streams for the currrent transit."""
# Find where transit starts and ends
if len(self.tstreams) == 0 or self.cur_transit is None:
self.log.info("Did not find any transits.")
return None
self.log.debug(
"Finalising transit for {}...".format(
ephem.unix_to_datetime(self.cur_transit)
)
)
all_t = np.concatenate([ts.time for ts in self.tstreams])
start_ind = int(np.argmin(np.abs(all_t - self.start_t)))
stop_ind = int(np.argmin(np.abs(all_t - self.end_t)))
# Save list of filenames
filenames = [ts.attrs["filename"] for ts in self.tstreams]
dt = self.tstreams[0].time[1] - self.tstreams[0].time[0]
if dt <= 0:
self.log.warning(
"Time steps are not positive definite: dt={:.3f}".format(dt)
+ " Skipping."
)
ts = None
if stop_ind - start_ind > int(self.min_span / 360.0 * SIDEREAL_DAY_SEC / dt):
if len(self.tstreams) > 1:
# Concatenate timestreams
ts = tod.concatenate(self.tstreams, start=start_ind, stop=stop_ind)
else:
ts = self.tstreams[0]
_, dec = ephem.object_coords(
self.src, all_t[0], deg=True, obs=self.observer
)
ts.attrs["dec"] = dec
ts.attrs["source_name"] = self.source
ts.attrs["transit_time"] = self.cur_transit
ts.attrs["observation_id"] = self.obs_id
ts.attrs["tag"] = "{}_{:0>4d}_{}".format(
self.source,
self.obs_id,
ephem.unix_to_datetime(self.cur_transit).strftime("%Y%m%dT%H%M%S"),
)
ts.attrs["archivefiles"] = filenames
else:
self.log.info("Transit too short. Skipping.")
ts = None
self.tstreams = []
self.cur_transit = None
return ts
def process(self, data):
"""Regrid visibility data onto a regular grid in hour angle.
Parameters
----------
data : TimeStream
Time-ordered data.
Returns
-------
new_data : SiderealStream
The regridded data centered on the source RA.
"""
# Redistribute if needed
data.redistribute("freq")
# View of data
weight = data.weight[:].view(np.ndarray)
vis_data = data.vis[:].view(np.ndarray)
# Get apparent source RA, including precession effects
ra, _ = ephem.object_coords(self.src, data.time[0], deg=True, obs=self.observer)
# Get catalogue RA for reference
ra_icrs, _ = ephem.object_coords(self.src, deg=True, obs=self.observer)
# Convert input times to hour angle
lha = unwrap_lha(self.observer.unix_to_lsa(data.time), ra)
# perform regridding
success = 1
try:
new_grid, new_vis, ni = self._regrid(vis_data, weight, lha)
except np.linalg.LinAlgError as e:
self.log.error(str(e))
success = 0
except ValueError as e:
self.log.error(str(e))
success = 0
# Check other ranks have completed
success = mpiutil.allreduce(success)
if success != mpiutil.size:
self.log.warning("Regridding failed. Skipping transit.")
return None
# mask out regions beyond bounds of this transit
grid_mask = np.ones_like(new_grid)
grid_mask[new_grid < lha.min()] = 0.0
grid_mask[new_grid > lha.max()] = 0.0
new_vis *= grid_mask
ni *= grid_mask
# Wrap to produce MPIArray
if data.distributed:
new_vis = mpiarray.MPIArray.wrap(new_vis, axis=data.vis.distributed_axis)
ni = mpiarray.MPIArray.wrap(ni, axis=data.vis.distributed_axis)
# Create new container for output
ra_grid = (new_grid + ra) % 360.0
new_data = SiderealStream(
axes_from=data, attrs_from=data, ra=ra_grid, comm=data.comm
)
new_data.redistribute("freq")
new_data.vis[:] = new_vis
new_data.weight[:] = ni
new_data.attrs["cirs_ra"] = ra
new_data.attrs["icrs_ra"] = ra_icrs
return new_data
def offline_point_source_calibration(file_list,
source,
inputmap=None,
start=None,
stop=None,
physical_freq=None,
tcorr=None,
logging_params=DEFAULT_LOGGING,
**kwargs):
# Load config
config = DEFAULTS.deepcopy()
config.merge(NameSpace(kwargs))
# Setup logging
log.setup_logging(logging_params)
mlog = log.get_logger(__name__)
mlog.info("ephemeris file: %s" % ephemeris.__file__)
# Set the model to use
fitter_function = utils.fit_point_source_transit
model_function = utils.model_point_source_transit
farg = inspect.getargspec(fitter_function)
defaults = {
key: val
for key, val in zip(farg.args[-len(farg.defaults):], farg.defaults)
}
poly_deg_amp = kwargs.get('poly_deg_amp', defaults['poly_deg_amp'])
poly_deg_phi = kwargs.get('poly_deg_phi', defaults['poly_deg_phi'])
poly_type = kwargs.get('poly_type', defaults['poly_type'])
param_name = ([
'%s_poly_amp_coeff%d' % (poly_type, cc)
for cc in range(poly_deg_amp + 1)
] + [
'%s_poly_phi_coeff%d' % (poly_type, cc)
for cc in range(poly_deg_phi + 1)
])
model_kwargs = [('poly_deg_amp', poly_deg_amp),
('poly_deg_phi', poly_deg_phi), ('poly_type', poly_type)]
model_name = '.'.join(
[getattr(model_function, key) for key in ['__module__', '__name__']])
tval = {}
# Set where to evaluate gain
ha_eval_str = ['raw_transit']
if config.multi_sample:
ha_eval_str += ['transit', 'peak']
ha_eval = [0.0, None]
fitslc = slice(1, 3)
ind_eval = ha_eval_str.index(config.evaluate_gain_at)
# Determine dimensions
direction = ['amp', 'phi']
nparam = len(param_name)
ngain = len(ha_eval_str)
ndir = len(direction)
# Determine frequencies
data = andata.CorrData.from_acq_h5(file_list,
datasets=(),
start=start,
stop=stop)
freq = data.freq
if physical_freq is not None:
index_freq = np.array(
[np.argmin(np.abs(ff - freq)) for ff in physical_freq])
freq_sel = utils.convert_to_slice(index_freq)
freq = freq[index_freq]
else:
index_freq = np.arange(freq.size)
freq_sel = None
nfreq = freq.size
# Compute flux of source
inv_rt_flux_density = tools.invert_no_zero(
np.sqrt(FluxCatalog[source].predict_flux(freq)))
# Read in the eigenvaluess for all frequencies
data = andata.CorrData.from_acq_h5(file_list,
datasets=['erms', 'eval'],
freq_sel=freq_sel,
start=start,
stop=stop)
# Determine source coordinates
this_csd = np.floor(ephemeris.unix_to_csd(np.median(data.time)))
timestamp0 = ephemeris.transit_times(FluxCatalog[source].skyfield,
ephemeris.csd_to_unix(this_csd))[0]
src_ra, src_dec = ephemeris.object_coords(FluxCatalog[source].skyfield,
date=timestamp0,
deg=True)
ra = ephemeris.lsa(data.time)
ha = ra - src_ra
ha = ha - (ha > 180.0) * 360.0 + (ha < -180.0) * 360.0
ha = np.radians(ha)
itrans = np.argmin(np.abs(ha))
window = 0.75 * np.max(np.abs(ha))
off_source = np.abs(ha) > window
mlog.info("CSD %d" % this_csd)
mlog.info("Hour angle at transit (%d of %d): %0.2f deg " %
(itrans, len(ha), np.degrees(ha[itrans])))
mlog.info("Hour angle off source: %0.2f deg" %
np.median(np.abs(np.degrees(ha[off_source]))))
src_dec = np.radians(src_dec)
lat = np.radians(ephemeris.CHIMELATITUDE)
# Determine division of frequencies
ninput = data.ninput
ntime = data.ntime
nblock_freq = int(np.ceil(nfreq / float(config.nfreq_per_block)))
# Determine bad inputs
eps = 10.0 * np.finfo(data['erms'].dtype).eps
good_freq = np.flatnonzero(np.all(data['erms'][:] > eps, axis=-1))
ind_sub_freq = good_freq[slice(0, good_freq.size,
max(int(good_freq.size / 10), 1))]
tmp_data = andata.CorrData.from_acq_h5(file_list,
datasets=['evec'],
freq_sel=ind_sub_freq,
start=start,
stop=stop)
eps = 10.0 * np.finfo(tmp_data['evec'].dtype).eps
bad_input = np.flatnonzero(
np.all(np.abs(tmp_data['evec'][:, 0]) < eps, axis=(0, 2)))
input_axis = tmp_data.input.copy()
del tmp_data
# Query layout database for correlator inputs
if inputmap is None:
inputmap = tools.get_correlator_inputs(
datetime.datetime.utcfromtimestamp(data.time[itrans]),
correlator='chime')
inputmap = tools.reorder_correlator_inputs(input_axis, inputmap)
tools.change_chime_location(rotation=config.telescope_rotation)
# Determine x and y pol index
xfeeds = np.array([
idf for idf, inp in enumerate(inputmap)
if (idf not in bad_input) and tools.is_array_x(inp)
])
yfeeds = np.array([
idf for idf, inp in enumerate(inputmap)
if (idf not in bad_input) and tools.is_array_y(inp)
])
nfeed = xfeeds.size + yfeeds.size
pol = [yfeeds, xfeeds]
polstr = ['Y', 'X']
npol = len(pol)
neigen = min(max(npol, config.neigen), data['eval'].shape[1])
phase_ref = config.phase_reference_index
phase_ref_by_pol = [
pol[pp].tolist().index(phase_ref[pp]) for pp in range(npol)
]
# Calculate dynamic range
eval0_off_source = np.median(data['eval'][:, 0, off_source], axis=-1)
dyn = data['eval'][:, 1, :] * tools.invert_no_zero(
eval0_off_source[:, np.newaxis])
# Determine frequencies to mask
not_rfi = np.ones((nfreq, 1), dtype=np.bool)
if config.mask_rfi is not None:
for frng in config.mask_rfi:
not_rfi[:, 0] &= ((freq < frng[0]) | (freq > frng[1]))
mlog.info("%0.1f percent of frequencies available after masking RFI." %
(100.0 * np.sum(not_rfi, dtype=np.float32) / float(nfreq), ))
#dyn_flg = utils.contiguous_flag(dyn > config.dyn_rng_threshold, centre=itrans)
if source in config.dyn_rng_threshold:
dyn_rng_threshold = config.dyn_rng_threshold[source]
else:
dyn_rng_threshold = config.dyn_rng_threshold.default
mlog.info("Dynamic range threshold set to %0.1f." % dyn_rng_threshold)
dyn_flg = dyn > dyn_rng_threshold
# Calculate fit flag
fit_flag = np.zeros((nfreq, npol, ntime), dtype=np.bool)
for pp in range(npol):
mlog.info("Dynamic Range Nsample, Pol %d: %s" % (pp, ','.join([
"%d" % xx for xx in np.percentile(np.sum(dyn_flg, axis=-1),
[25, 50, 75, 100])
])))
if config.nsigma1 is None:
fit_flag[:, pp, :] = dyn_flg & not_rfi
else:
fit_window = config.nsigma1 * np.radians(
utils.get_window(freq, pol=polstr[pp], dec=src_dec, deg=True))
win_flg = np.abs(ha)[np.newaxis, :] <= fit_window[:, np.newaxis]
fit_flag[:, pp, :] = (dyn_flg & win_flg & not_rfi)
# Calculate base error
base_err = data['erms'][:, np.newaxis, :]
# Check for sign flips
ref_resp = andata.CorrData.from_acq_h5(file_list,
datasets=['evec'],
input_sel=config.eigen_reference,
freq_sel=freq_sel,
start=start,
stop=stop)['evec'][:, 0:neigen,
0, :]
sign0 = 1.0 - 2.0 * (ref_resp.real < 0.0)
# Check that we have the correct reference feed
if np.any(np.abs(ref_resp.imag) > 0.0):
ValueError("Reference feed %d is incorrect." % config.eigen_reference)
del ref_resp
# Save index_map
results = {}
results['model'] = model_name
results['param'] = param_name
results['freq'] = data.index_map['freq'][:]
results['input'] = input_axis
results['eval'] = ha_eval_str
results['dir'] = direction
for key, val in model_kwargs:
results[key] = val
# Initialize numpy arrays to hold results
if config.return_response:
results['response'] = np.zeros((nfreq, ninput, ntime),
dtype=np.complex64)
results['response_err'] = np.zeros((nfreq, ninput, ntime),
dtype=np.float32)
results['fit_flag'] = fit_flag
results['ha_axis'] = ha
results['ra'] = ra
else:
results['gain_eval'] = np.zeros((nfreq, ninput, ngain),
dtype=np.complex64)
results['weight_eval'] = np.zeros((nfreq, ninput, ngain),
dtype=np.float32)
results['frac_gain_err'] = np.zeros((nfreq, ninput, ngain, ndir),
dtype=np.float32)
results['parameter'] = np.zeros((nfreq, ninput, nparam),
dtype=np.float32)
results['parameter_err'] = np.zeros((nfreq, ninput, nparam),
dtype=np.float32)
results['index_eval'] = np.full((nfreq, ninput), -1, dtype=np.int8)
results['gain'] = np.zeros((nfreq, ninput), dtype=np.complex64)
results['weight'] = np.zeros((nfreq, ninput), dtype=np.float32)
results['ndof'] = np.zeros((nfreq, ninput, ndir), dtype=np.float32)
results['chisq'] = np.zeros((nfreq, ninput, ndir), dtype=np.float32)
results['timing'] = np.zeros((nfreq, ninput), dtype=np.complex64)
# Initialize metric like variables
results['runtime'] = np.zeros((nblock_freq, 2), dtype=np.float64)
# Compute distances
dist = tools.get_feed_positions(inputmap)
for pp, feeds in enumerate(pol):
dist[feeds, :] -= dist[phase_ref[pp], np.newaxis, :]
# Loop over frequency blocks
for gg in range(nblock_freq):
mlog.info("Frequency block %d of %d." % (gg, nblock_freq))
fstart = gg * config.nfreq_per_block
fstop = min((gg + 1) * config.nfreq_per_block, nfreq)
findex = np.arange(fstart, fstop)
ngroup = findex.size
freq_sel = utils.convert_to_slice(index_freq[findex])
timeit_start_gg = time.time()
#
if config.return_response:
gstart = start
gstop = stop
tslc = slice(0, ntime)
else:
good_times = np.flatnonzero(np.any(fit_flag[findex], axis=(0, 1)))
if good_times.size == 0:
continue
gstart = int(np.min(good_times))
gstop = int(np.max(good_times)) + 1
tslc = slice(gstart, gstop)
gstart += start
gstop += start
hag = ha[tslc]
itrans = np.argmin(np.abs(hag))
# Load eigenvectors.
nudata = andata.CorrData.from_acq_h5(
file_list,
datasets=['evec', 'vis', 'flags/vis_weight'],
apply_gain=False,
freq_sel=freq_sel,
start=gstart,
stop=gstop)
# Save time to load data
results['runtime'][gg, 0] = time.time() - timeit_start_gg
timeit_start_gg = time.time()
mlog.info("Time to load (per frequency): %0.3f sec" %
(results['runtime'][gg, 0] / ngroup, ))
# Loop over polarizations
for pp, feeds in enumerate(pol):
# Get timing correction
if tcorr is not None:
tgain = tcorr.get_gain(nudata.freq, nudata.input[feeds],
nudata.time)
tgain *= tgain[:, phase_ref_by_pol[pp], np.newaxis, :].conj()
tgain_transit = tgain[:, :, itrans].copy()
tgain *= tgain_transit[:, :, np.newaxis].conj()
# Create the polarization masking vector
P = np.zeros((1, ninput, 1), dtype=np.float64)
P[:, feeds, :] = 1.0
# Loop over frequencies
for gff, ff in enumerate(findex):
flg = fit_flag[ff, pp, tslc]
if (2 * int(np.sum(flg))) < (nparam +
1) and not config.return_response:
continue
# Normalize by eigenvalue and correct for pi phase flips in process.
resp = (nudata['evec'][gff, 0:neigen, :, :] *
np.sqrt(data['eval'][ff, 0:neigen, np.newaxis, tslc]) *
sign0[ff, :, np.newaxis, tslc])
# Rotate to single-pol response
# Move time to first axis for the matrix multiplication
invL = tools.invert_no_zero(
np.rollaxis(data['eval'][ff, 0:neigen, np.newaxis, tslc],
-1, 0))
UT = np.rollaxis(resp, -1, 0)
U = np.swapaxes(UT, -1, -2)
mu, vp = np.linalg.eigh(np.matmul(UT.conj(), P * U))
rsign0 = (1.0 - 2.0 * (vp[:, 0, np.newaxis, :].real < 0.0))
resp = mu[:, np.newaxis, :] * np.matmul(U, rsign0 * vp * invL)
# Extract feeds of this pol
# Transpose so that time is back to last axis
resp = resp[:, feeds, -1].T
# Compute error on response
dataflg = ((nudata.weight[gff, feeds, :] > 0.0)
& np.isfinite(nudata.weight[gff, feeds, :])).astype(
np.float32)
resp_err = dataflg * base_err[ff, :, tslc] * np.sqrt(
nudata.vis[gff, feeds, :].real) * tools.invert_no_zero(
np.sqrt(mu[np.newaxis, :, -1]))
# Reference to specific input
resp *= np.exp(
-1.0J *
np.angle(resp[phase_ref_by_pol[pp], np.newaxis, :]))
# Apply timing correction
if tcorr is not None:
resp *= tgain[gff]
results['timing'][ff, feeds] = tgain_transit[gff]
# Fringestop
lmbda = scipy.constants.c * 1e-6 / nudata.freq[gff]
resp *= tools.fringestop_phase(
hag[np.newaxis, :], lat, src_dec,
dist[feeds, 0, np.newaxis] / lmbda,
dist[feeds, 1, np.newaxis] / lmbda)
# Normalize by source flux
resp *= inv_rt_flux_density[ff]
resp_err *= inv_rt_flux_density[ff]
# If requested, reference phase to the median value
if config.med_phase_ref:
phi0 = np.angle(resp[:, itrans, np.newaxis])
resp *= np.exp(-1.0J * phi0)
resp *= np.exp(
-1.0J *
np.median(np.angle(resp), axis=0, keepdims=True))
resp *= np.exp(1.0J * phi0)
# Check if return_response flag was set by user
if not config.return_response:
if config.multi_sample:
moving_window = config.nsigma2 and config.nsigma2 * np.radians(
utils.get_window(nudata.freq[gff],
pol=polstr[pp],
dec=src_dec,
deg=True))
# Loop over inputs
for pii, ii in enumerate(feeds):
is_good = flg & (np.abs(resp[pii, :]) >
0.0) & (resp_err[pii, :] > 0.0)
# Set the intial gains based on raw response at transit
if is_good[itrans]:
results['gain_eval'][ff, ii,
0] = tools.invert_no_zero(
resp[pii, itrans])
results['frac_gain_err'][ff, ii, 0, :] = (
resp_err[pii, itrans] * tools.invert_no_zero(
np.abs(resp[pii, itrans])))
results['weight_eval'][ff, ii, 0] = 0.5 * (
np.abs(resp[pii, itrans])**2 *
tools.invert_no_zero(resp_err[pii, itrans]))**2
results['index_eval'][ff, ii] = 0
results['gain'][ff,
ii] = results['gain_eval'][ff, ii,
0]
results['weight'][ff,
ii] = results['weight_eval'][ff,
ii,
0]
# Exit if not performing multi time sample fit
if not config.multi_sample:
continue
if (2 * int(np.sum(is_good))) < (nparam + 1):
continue
try:
param, param_err, gain, gain_err, ndof, chisq, tval = fitter_function(
hag[is_good],
resp[pii, is_good],
resp_err[pii, is_good],
ha_eval,
window=moving_window,
tval=tval,
**config.fit)
except Exception as rex:
if config.verbose:
mlog.info(
"Frequency %0.2f, Feed %d failed with error: %s"
% (nudata.freq[gff], ii, rex))
continue
# Check for nan
wfit = (np.abs(gain) *
tools.invert_no_zero(np.abs(gain_err)))**2
if np.any(~np.isfinite(np.abs(gain))) or np.any(
~np.isfinite(wfit)):
continue
# Save to results using the convention that you should *multiply* the visibilites by the gains
results['gain_eval'][
ff, ii, fitslc] = tools.invert_no_zero(gain)
results['frac_gain_err'][ff, ii, fitslc,
0] = gain_err.real
results['frac_gain_err'][ff, ii, fitslc,
1] = gain_err.imag
results['weight_eval'][ff, ii, fitslc] = wfit
results['parameter'][ff, ii, :] = param
results['parameter_err'][ff, ii, :] = param_err
results['ndof'][ff, ii, :] = ndof
results['chisq'][ff, ii, :] = chisq
# Check if the fit was succesful and update the gain evaluation index appropriately
if np.all((chisq / ndof.astype(np.float32)
) <= config.chisq_per_dof_threshold):
results['index_eval'][ff, ii] = ind_eval
results['gain'][ff, ii] = results['gain_eval'][
ff, ii, ind_eval]
results['weight'][ff, ii] = results['weight_eval'][
ff, ii, ind_eval]
else:
# Return response only (do not fit model)
results['response'][ff, feeds, :] = resp
results['response_err'][ff, feeds, :] = resp_err
# Save time to fit data
results['runtime'][gg, 1] = time.time() - timeit_start_gg
mlog.info("Time to fit (per frequency): %0.3f sec" %
(results['runtime'][gg, 1] / ngroup, ))
# Clean up
del nudata
gc.collect()
# Print total run time
mlog.info("TOTAL TIME TO LOAD: %0.3f min" %
(np.sum(results['runtime'][:, 0]) / 60.0, ))
mlog.info("TOTAL TIME TO FIT: %0.3f min" %
(np.sum(results['runtime'][:, 1]) / 60.0, ))
# Set the best estimate of the gain
if not config.return_response:
flag = results['index_eval'] >= 0
gain = results['gain']
# Compute amplitude
amp = np.abs(gain)
# Hard cutoffs on the amplitude
med_amp = np.median(amp[flag])
min_amp = med_amp * config.min_amp_scale_factor
max_amp = med_amp * config.max_amp_scale_factor
flag &= ((amp >= min_amp) & (amp <= max_amp))
# Flag outliers in amplitude for each frequency
for pp, feeds in enumerate(pol):
med_amp_by_pol = np.zeros(nfreq, dtype=np.float32)
sig_amp_by_pol = np.zeros(nfreq, dtype=np.float32)
for ff in range(nfreq):
this_flag = flag[ff, feeds]
if np.any(this_flag):
med, slow, shigh = utils.estimate_directional_scale(
amp[ff, feeds[this_flag]])
lower = med - config.nsigma_outlier * slow
upper = med + config.nsigma_outlier * shigh
flag[ff, feeds] &= ((amp[ff, feeds] >= lower) &
(amp[ff, feeds] <= upper))
med_amp_by_pol[ff] = med
sig_amp_by_pol[ff] = 0.5 * (shigh - slow) / np.sqrt(
np.sum(this_flag, dtype=np.float32))
if config.nsigma_med_outlier:
med_flag = med_amp_by_pol > 0.0
not_outlier = flag_outliers(med_amp_by_pol,
med_flag,
window=config.window_med_outlier,
nsigma=config.nsigma_med_outlier)
flag[:, feeds] &= not_outlier[:, np.newaxis]
mlog.info("Pol %s: %d frequencies are outliers." %
(polstr[pp],
np.sum(~not_outlier & med_flag, dtype=np.int)))
# Determine bad frequencies
flag_freq = (np.sum(flag, axis=1, dtype=np.float32) /
float(ninput)) > config.threshold_good_freq
good_freq = np.flatnonzero(flag_freq)
# Determine bad inputs
fraction_good = np.sum(flag[good_freq, :], axis=0,
dtype=np.float32) / float(good_freq.size)
flag_input = fraction_good > config.threshold_good_input
# Finalize flag
flag &= (flag_freq[:, np.newaxis] & flag_input[np.newaxis, :])
# Interpolate gains
interp_gain, interp_weight = interpolate_gain(
freq,
gain,
results['weight'],
flag=flag,
length_scale=config.interpolation_length_scale,
mlog=mlog)
# Save gains to object
results['flag'] = flag
results['gain'] = interp_gain
results['weight'] = interp_weight
# Return results
return results