def _fit_position_tsmap(self, name, **kwargs):
"""Localize a source from its TS map."""
prefix = kwargs.get('prefix', '')
dtheta_max = kwargs.get('dtheta_max', 0.5)
zmin = kwargs.get('zmin', -3.0)
kw = {
'map_size': 2.0 * dtheta_max,
'write_fits': kwargs.get('write_fits', False),
'write_npy': kwargs.get('write_npy', False),
'use_pylike': kwargs.get('use_pylike', True),
'max_kernel_radius': self.config['tsmap']['max_kernel_radius'],
'loglevel': logging.DEBUG
}
src = self.roi.copy_source(name)
if src['SpatialModel'] in ['RadialDisk', 'RadialGaussian']:
kw['max_kernel_radius'] = max(kw['max_kernel_radius'],
2.0 * src['SpatialWidth'])
skydir = kwargs.get('skydir', src.skydir)
tsmap = self.tsmap(utils.join_strings([prefix, name.lower().
replace(' ', '_')]),
model=src.data,
map_skydir=skydir,
exclude=[name],
make_plots=False, **kw)
# Find peaks with TS > 4
peaks = find_peaks(tsmap['ts'], 4.0, 0.2)
peak_best = None
o = {}
for p in sorted(peaks, key=lambda t: t['amp'], reverse=True):
xy = p['ix'], p['iy']
ts_value = tsmap['ts'].data[xy[1], xy[0]]
posfit = fit_error_ellipse(tsmap['ts'], xy=xy, dpix=2,
zmin=max(zmin, -ts_value * 0.5))
offset = posfit['skydir'].separation(self.roi[name].skydir).deg
if posfit['fit_success'] and posfit['fit_inbounds']:
peak_best = p
break
if peak_best is None:
ts_value = np.max(tsmap['ts'].data)
posfit = fit_error_ellipse(tsmap['ts'], dpix=2,
zmin=max(zmin, -ts_value * 0.5))
o.update(posfit)
pix = posfit['skydir'].to_pixel(self.geom.wcs)
o['xpix'] = float(pix[0])
o['ypix'] = float(pix[1])
o['skydir'] = posfit['skydir'].transform_to('icrs')
o['pos_offset'] = posfit['skydir'].separation(
self.roi[name].skydir).deg
o['loglike'] = 0.5 * posfit['zoffset']
o['tsmap'] = tsmap['ts']
return o
def _fit_position_tsmap(self, name, **kwargs):
"""Localize a source from its TS map."""
prefix = kwargs.get('prefix', '')
dtheta_max = kwargs.get('dtheta_max', 0.5)
zmin = kwargs.get('zmin', -3.0)
kw = {
'map_size': 2.0 * dtheta_max,
'write_fits': kwargs.get('write_fits', False),
'write_npy': kwargs.get('write_npy', False),
'use_pylike': kwargs.get('use_pylike', True),
'max_kernel_radius': self.config['tsmap']['max_kernel_radius'],
'loglevel': logging.DEBUG
}
src = self.roi.copy_source(name)
if src['SpatialModel'] in ['RadialDisk', 'RadialGaussian']:
kw['max_kernel_radius'] = max(kw['max_kernel_radius'],
2.0 * src['SpatialWidth'])
skydir = kwargs.get('skydir', src.skydir)
tsmap = self.tsmap(utils.join_strings([prefix, name.lower().
replace(' ', '_')]),
model=src.data,
map_skydir=skydir,
exclude=[name],
make_plots=False, **kw)
# Find peaks with TS > 4
peaks = find_peaks(tsmap['ts'], 4.0, 0.2)
peak_best = None
o = {}
for p in sorted(peaks, key=lambda t: t['amp'], reverse=True):
xy = p['ix'], p['iy']
ts_value = tsmap['ts'].counts[xy[1], xy[0]]
posfit = fit_error_ellipse(tsmap['ts'], xy=xy, dpix=2,
zmin=max(zmin, -ts_value * 0.5))
offset = posfit['skydir'].separation(self.roi[name].skydir).deg
if posfit['fit_success'] and posfit['fit_inbounds']:
peak_best = p
break
if peak_best is None:
ts_value = np.max(tsmap['ts'].counts)
posfit = fit_error_ellipse(tsmap['ts'], dpix=2,
zmin=max(zmin, -ts_value * 0.5))
o.update(posfit)
pix = posfit['skydir'].to_pixel(self._skywcs)
o['xpix'] = float(pix[0])
o['ypix'] = float(pix[1])
o['skydir'] = posfit['skydir'].transform_to('icrs')
o['pos_offset'] = posfit['skydir'].separation(
self.roi[name].skydir).deg
o['loglike'] = 0.5 * posfit['zoffset']
o['tsmap'] = tsmap['ts']
return o
def _localize_tsmap(self, name, **kwargs):
"""Localize a source from its TS map."""
prefix = kwargs.get('prefix', '')
dtheta_max = kwargs.get('dtheta_max', 0.5)
write_fits = kwargs.get('write_fits', False)
write_npy = kwargs.get('write_npy', False)
src = self.roi.copy_source(name)
skydir = src.skydir
skywcs = self._skywcs
tsmap = self.tsmap(utils.join_strings(
[prefix, name.lower().replace(' ', '_')]),
model=src.data,
map_skydir=skydir,
map_size=2.0 * dtheta_max,
exclude=[name],
write_fits=write_fits,
write_npy=write_npy,
make_plots=False)
posfit, skydir = fit_error_ellipse(tsmap['ts'], dpix=2)
pix = skydir.to_pixel(skywcs)
o = {}
o.update(posfit)
o['xpix'] = float(pix[0])
o['ypix'] = float(pix[1])
return o, tsmap
def _build_src_dicts_from_peaks(self, peaks, maps, src_dict_template):
tsmap = maps['ts']
amp = maps['amplitude']
src_dicts = []
names = []
for p in peaks:
o = fit_error_ellipse(tsmap, (p['ix'], p['iy']), dpix=2)
skydir = o['skydir']
p['fit_loc'] = o
p['fit_skydir'] = o['skydir']
p.update(o)
name = utils.create_source_name(skydir)
src_dict = copy.deepcopy(src_dict_template)
norm_par = get_function_norm_par_name(
src_dict_template['SpectrumType'])
src_dict.update({
norm_par: amp.data[p['iy'], p['ix']],
'ra': skydir.icrs.ra.deg,
'dec': skydir.icrs.dec.deg
})
src_dict['glon_err'] = o['glon_err']
src_dict['glat_err'] = o['glat_err']
src_dict['ra_err'] = o['ra_err']
src_dict['dec_err'] = o['dec_err']
src_dict['pos_err'] = o['pos_err']
src_dict['pos_err_semimajor'] = o['pos_err_semimajor']
src_dict['pos_err_semiminor'] = o['pos_err_semiminor']
src_dict['pos_r68'] = o['pos_r68']
src_dict['pos_r95'] = o['pos_r95']
src_dict['pos_r99'] = o['pos_r99']
src_dict['pos_angle'] = o['pos_angle']
src_dict['pos_gal_cov'] = o['pos_gal_cov']
src_dict['pos_gal_corr'] = o['pos_gal_corr']
src_dict['pos_cel_cov'] = o['pos_cel_cov']
src_dict['pos_cel_corr'] = o['pos_cel_corr']
self.logger.info('Found source\n' + 'name: %s\n' % name +
'ts: %f' % p['amp']**2)
names.append(name)
src_dicts.append(src_dict)
return names, src_dicts
def _build_src_dicts_from_peaks(self, peaks, maps, src_dict_template):
tsmap = maps['ts']
amp = maps['amplitude']
src_dicts = []
names = []
for p in peaks:
o = fit_error_ellipse(tsmap, (p['ix'], p['iy']), dpix=2)
skydir = o['skydir']
p['fit_loc'] = o
p['fit_skydir'] = o['skydir']
p.update(o)
name = utils.create_source_name(skydir)
src_dict = copy.deepcopy(src_dict_template)
norm_par = get_function_norm_par_name(
src_dict_template['SpectrumType'])
src_dict.update({norm_par: amp.counts[p['iy'], p['ix']],
'ra': skydir.icrs.ra.deg,
'dec': skydir.icrs.dec.deg})
src_dict['glon_err'] = o['glon_err']
src_dict['glat_err'] = o['glat_err']
src_dict['ra_err'] = o['ra_err']
src_dict['dec_err'] = o['dec_err']
src_dict['pos_err'] = o['pos_err']
src_dict['pos_err_semimajor'] = o['pos_err_semimajor']
src_dict['pos_err_semiminor'] = o['pos_err_semiminor']
src_dict['pos_r68'] = o['pos_r68']
src_dict['pos_r95'] = o['pos_r95']
src_dict['pos_r99'] = o['pos_r99']
src_dict['pos_angle'] = o['pos_angle']
src_dict['pos_gal_cov'] = o['pos_gal_cov']
src_dict['pos_gal_corr'] = o['pos_gal_corr']
src_dict['pos_cel_cov'] = o['pos_cel_cov']
src_dict['pos_cel_corr'] = o['pos_cel_corr']
self.logger.info('Found source\n' +
'name: %s\n' % name +
'ts: %f' % p['amp'] ** 2)
names.append(name)
src_dicts.append(src_dict)
return names, src_dicts
def _build_src_dicts_from_peaks(self, peaks, maps, src_dict_template):
tsmap = maps['ts']
amp = maps['amplitude']
src_dicts = []
names = []
for p in peaks:
o, skydir = fit_error_ellipse(tsmap, (p['ix'], p['iy']), dpix=2)
p['fit_loc'] = o
p['fit_skydir'] = skydir
p.update(o)
if o['fit_success']:
skydir = p['fit_skydir']
else:
skydir = p['skydir']
name = utils.create_source_name(skydir)
src_dict = copy.deepcopy(src_dict_template)
src_dict.update({
'Prefactor': amp.counts[p['iy'], p['ix']],
'ra': skydir.icrs.ra.deg,
'dec': skydir.icrs.dec.deg
})
src_dict['pos_sigma'] = o['sigma']
src_dict['pos_sigma_semimajor'] = o['sigma_semimajor']
src_dict['pos_sigma_semiminor'] = o['sigma_semiminor']
src_dict['pos_r68'] = o['r68']
src_dict['pos_r95'] = o['r95']
src_dict['pos_r99'] = o['r99']
src_dict['pos_angle'] = np.degrees(o['theta'])
self.logger.info('Found source\n' + 'name: %s\n' % name +
'ts: %f' % p['amp']**2)
names.append(name)
src_dicts.append(src_dict)
return names, src_dicts
def _fit_position_scan(self, name, **kwargs):
zmin = kwargs.get('zmin', -9.0)
tsmap, loglike = self._scan_position(name, **kwargs)
ts_value = np.max(tsmap.data)
posfit = fit_error_ellipse(tsmap, dpix=2,
zmin=max(zmin, -ts_value * 0.5))
pix = posfit['skydir'].to_pixel(self.geom.wcs)
o = {}
o.update(posfit)
o['xpix'] = float(pix[0])
o['ypix'] = float(pix[1])
o['skydir'] = posfit['skydir'].transform_to('icrs')
o['pos_offset'] = posfit['skydir'].separation(
self.roi[name].skydir).deg
o['loglike'] = 0.5 * posfit['zoffset'] + loglike
o['tsmap'] = tsmap
return o
def _fit_position_scan(self, name, **kwargs):
zmin = kwargs.get('zmin', -9.0)
tsmap, loglike = self._scan_position(name, **kwargs)
ts_value = np.max(tsmap.counts)
posfit = fit_error_ellipse(tsmap, dpix=2,
zmin=max(zmin, -ts_value * 0.5))
pix = posfit['skydir'].to_pixel(self._skywcs)
o = {}
o.update(posfit)
o['xpix'] = float(pix[0])
o['ypix'] = float(pix[1])
o['skydir'] = posfit['skydir'].transform_to('icrs')
o['pos_offset'] = posfit['skydir'].separation(
self.roi[name].skydir).deg
o['loglike'] = 0.5 * posfit['zoffset'] + loglike
o['tsmap'] = tsmap
return o
def localize(self, name, **kwargs):
"""Find the best-fit position of a source. Localization is
performed in two steps. First a TS map is computed centered
on the source with half-width set by ``dtheta_max``. A fit is
then performed to the maximum TS peak in this map. The source
position is then further refined by scanning the likelihood in
the vicinity of the peak found in the first step. The size of
the scan region is set to encompass the 99% positional
uncertainty contour as determined from the peak fit.
Parameters
----------
name : str
Source name.
dtheta_max : float
Maximum offset in RA/DEC in deg from the nominal source
position that will be used to define the boundaries of the
TS map search region.
nstep : int
Number of steps in longitude/latitude that will be taken
when refining the source position. The bounds of the scan
range are set to the 99% positional uncertainty as
determined from the TS map peak fit. The total number of
sampling points will be nstep**2.
fix_background : bool
Fix background parameters when fitting the source position.
update : bool
Update the model for this source with the best-fit
position. If newname=None this will overwrite the
existing source map of this source with one corresponding
to its new location.
newname : str
Name that will be assigned to the relocalized source
when update=True. If newname is None then the existing
source name will be used.
make_plots : bool
Generate plots.
write_fits : bool
Write the output to a FITS file.
write_npy : bool
Write the output dictionary to a numpy file.
optimizer : dict
Dictionary that overrides the default optimizer settings.
Returns
-------
localize : dict
Dictionary containing results of the localization
analysis. This dictionary is also saved to the
dictionary of this source in 'localize'.
"""
name = self.roi.get_source_by_name(name).name
schema = ConfigSchema(self.defaults['localize'],
optimizer=self.defaults['optimizer'])
schema.add_option('make_plots', False)
schema.add_option('write_fits', True)
schema.add_option('write_npy', True)
schema.add_option('newname', name)
schema.add_option('prefix', '')
config = utils.create_dict(self.config['localize'],
optimizer=self.config['optimizer'])
config = schema.create_config(config, **kwargs)
nstep = config['nstep']
dtheta_max = config['dtheta_max']
update = config['update']
newname = config['newname']
prefix = config['prefix']
self.logger.info('Running localization for %s' % name)
saved_state = LikelihoodState(self.like)
if config['fix_background']:
self.free_sources(free=False, loglevel=logging.DEBUG)
src = self.roi.copy_source(name)
skydir = src.skydir
skywcs = self._skywcs
src_pix = skydir.to_pixel(skywcs)
tsmap_fit, tsmap = self._localize_tsmap(name,
prefix=prefix,
dtheta_max=dtheta_max)
self.logger.debug(
'Completed localization with TS Map.\n'
'(ra,dec) = (%10.4f,%10.4f)\n'
'(glon,glat) = (%10.4f,%10.4f)', tsmap_fit['ra'], tsmap_fit['dec'],
tsmap_fit['glon'], tsmap_fit['glat'])
# Fit baseline (point-source) model
self.free_norm(name)
fit_output = self._fit(loglevel=logging.DEBUG, **config['optimizer'])
# Save likelihood value for baseline fit
loglike0 = fit_output['loglike']
self.logger.debug('Baseline Model Likelihood: %f', loglike0)
self.zero_source(name)
o = {
'name': name,
'config': config,
'fit_success': True,
'loglike_base': loglike0,
'loglike_loc': np.nan,
'dloglike_loc': np.nan
}
cdelt0 = np.abs(skywcs.wcs.cdelt[0])
cdelt1 = np.abs(skywcs.wcs.cdelt[1])
scan_step = 2.0 * tsmap_fit['r95'] / (nstep - 1.0)
self.logger.debug(
'Refining localization search to '
'region of width: %.4f deg', tsmap_fit['r95'])
scan_map = Map.create(SkyCoord(tsmap_fit['ra'],
tsmap_fit['dec'],
unit='deg'),
scan_step, (nstep, nstep),
coordsys=wcs_utils.get_coordsys(skywcs))
scan_skydir = scan_map.get_pixel_skydirs()
lnlscan = dict(wcs=scan_map.wcs.to_header().items(),
loglike=np.zeros((nstep, nstep)),
dloglike=np.zeros((nstep, nstep)),
dloglike_fit=np.zeros((nstep, nstep)))
for i, t in enumerate(scan_skydir):
model_name = '%s_localize' % (name.replace(' ', '').lower())
src.set_name(model_name)
src.set_position(t)
self.add_source(model_name,
src,
free=True,
init_source=False,
save_source_maps=False,
loglevel=logging.DEBUG)
fit_output = self._fit(loglevel=logging.DEBUG,
**config['optimizer'])
loglike1 = fit_output['loglike']
lnlscan['loglike'].flat[i] = loglike1
self.delete_source(model_name, loglevel=logging.DEBUG)
lnlscan['dloglike'] = lnlscan['loglike'] - np.max(lnlscan['loglike'])
scan_tsmap = Map(2.0 * lnlscan['dloglike'].T, scan_map.wcs)
self.unzero_source(name)
saved_state.restore()
self._sync_params(name)
self._update_roi()
scan_fit, new_skydir = fit_error_ellipse(scan_tsmap, dpix=3)
o.update(scan_fit)
o['loglike_loc'] = np.max(
lnlscan['loglike']) + 0.5 * scan_fit['offset']
o['dloglike_loc'] = o['loglike_loc'] - o['loglike_base']
# lnlscan['dloglike_fit'] = \
# utils.parabola(np.linspace(0,nstep-1.0,nstep)[:,np.newaxis],
# np.linspace(0,nstep-1.0,nstep)[np.newaxis,:],
# *scan_fit['popt']).reshape((nstep,nstep))
o['lnlscan'] = lnlscan
# Best fit position and uncertainty from fit to TS map
o['tsmap_fit'] = tsmap_fit
# Best fit position and uncertainty from pylike scan
o['scan_fit'] = scan_fit
pix = new_skydir.to_pixel(skywcs)
o['xpix'] = float(pix[0])
o['ypix'] = float(pix[1])
o['deltax'] = (o['xpix'] - src_pix[0]) * cdelt0
o['deltay'] = (o['ypix'] - src_pix[1]) * cdelt1
o['offset'] = skydir.separation(new_skydir).deg
if o['offset'] > dtheta_max:
o['fit_success'] = False
if not o['fit_success']:
self.logger.error(
'Localization failed.\n'
'(ra,dec) = (%10.4f,%10.4f)\n'
'(glon,glat) = (%10.4f,%10.4f)\n'
'offset = %8.4f deltax = %8.4f '
'deltay = %8.4f', o['ra'], o['dec'], o['glon'], o['glat'],
o['offset'], o['deltax'], o['deltay'])
else:
self.logger.info(
'Localization succeeded with '
'coordinates:\n'
'(ra,dec) = (%10.4f,%10.4f)\n'
'(glon,glat) = (%10.4f,%10.4f)\n'
'offset = %8.4f r68 = %8.4f', o['ra'], o['dec'], o['glon'],
o['glat'], o['offset'], o['r68'])
self.roi[name]['localize'] = copy.deepcopy(o)
if config['make_plots']:
self._plotter.make_localization_plots(o,
tsmap,
self.roi,
prefix=prefix,
skydir=scan_skydir)
if update and o['fit_success']:
self.logger.info('Updating source %s '
'to localized position.', name)
src = self.delete_source(name)
src.set_position(new_skydir)
src.set_name(newname, names=src.names)
self.add_source(newname, src, free=True)
fit_output = self.fit(loglevel=logging.DEBUG)
o['loglike_loc'] = fit_output['loglike']
o['dloglike_loc'] = o['loglike_loc'] - o['loglike_base']
src = self.roi.get_source_by_name(newname)
self.roi[newname]['localize'] = copy.deepcopy(o)
self.logger.info('LogLike: %12.3f DeltaLogLike: %12.3f',
o['loglike_loc'], o['dloglike_loc'])
if o['fit_success']:
src = self.roi.get_source_by_name(newname)
src['pos_sigma'] = o['sigma']
src['pos_sigma_semimajor'] = o['sigma_semimajor']
src['pos_sigma_semiminor'] = o['sigma_semiminor']
src['pos_r68'] = o['r68']
src['pos_r95'] = o['r95']
src['pos_r99'] = o['r99']
src['pos_angle'] = np.degrees(o['theta'])
self.logger.info('Finished localization.')
return o
