def write_healpix_map(skylocs,
nside=16,
outdir='./',
enable_multiresolution=False,
fitsoutname='skymap.fits.gz',
nest=True):
"""
Construct a sky map of the sky localization posterior distribution
using Healpix
Parameters
==========
skylocs : 2d numpy array
sky location angle matrix of size Nsamples x 2 [radians]
logpvals : array_like
log posterior probability values, vector of size Nsamples
contour : float or None
plot contour enclosing this percentage of probability mass [may be
specified multiple times, default: none]
theta = EclipticLatitude + np.pi / 2,
phi = EclipticLongitude - np.pi
"""
# Conversion to Ecliptic latitude and longitude
latitude = skylocs[:, 0] - np.pi / 2
longitude = skylocs[:, 1] + np.pi
# Should we concert into degrees?
# latitude *= 180 / np.pi
# longitude *= 180 / np.pi
# convert angles in right ascension and declination
pts = np.column_stack((longitude, latitude))
# Create instance of 2D KDE class
skypost = kde.Clustered2DSkyKDE(pts)
# # Pickle the skyposterior object
# with open(os.path.join(outdir, 'skypost.obj'), 'wb') as out:
# pickle.dump(skypost, out)
# Making skymap
hpmap = skypost.as_healpix()
if not enable_multiresolution:
hpmap = bayestar.rasterize(hpmap)
# Include metadata
hpmap.meta.update(io.fits.metadata_for_version_module(version))
hpmap.meta['creator'] = 'Q. Baghi'
hpmap.meta['origin'] = 'LISA'
hpmap.meta['gps_creation_time'] = Time.now().gps
# Write skymap to file if needed
io.write_sky_map(os.path.join(outdir, fitsoutname), hpmap, nest=nest)
def localization_observability_for_date(dateobs, localization_name, date):
localization = one_or_404(
models.Localization.query.filter_by(
dateobs=dateobs, localization_name=localization_name))
names, lons, lats, heights = zip(*((t.telescope, str(t.lon), str(t.lat),
str(t.elevation))
for t in models.Telescope.query))
with \
tempfile.NamedTemporaryFile(suffix='.fits') as fitsfile, \
tempfile.NamedTemporaryFile(suffix='.png') as imgfile, \
matplotlib.style.context('default'):
io.write_sky_map(fitsfile.name, localization.table_2d, moc=True)
plot_observability([
'--site-name', *names, '--site-longitude', *lons,
'--site-latitude', *lats, '--site-height', *heights, '--time',
date.isoformat(), fitsfile.name, '-o', imgfile.name
])
contents = imgfile.read()
return Response(contents, mimetype='image/png')
def localization_airmass_for_date(dateobs, telescope, localization_name, date):
localization = one_or_404(
models.Localization.query.filter_by(
dateobs=dateobs, localization_name=localization_name))
telescope = models.Telescope.query.get_or_404(telescope)
with \
tempfile.NamedTemporaryFile(suffix='.fits') as fitsfile, \
tempfile.NamedTemporaryFile(suffix='.png') as imgfile, \
matplotlib.style.context('default'):
io.write_sky_map(fitsfile.name, localization.table_2d, moc=True)
plot_airmass([
'--site-longitude',
str(telescope.lon), '--site-latitude',
str(telescope.lat), '--site-height',
str(telescope.elevation), '--site-timezone', telescope.timezone,
'--time',
date.isoformat(), fitsfile.name, '-o', imgfile.name
])
contents = imgfile.read()
return Response(contents, mimetype='image/png')
def plot_skymap(self,
maxpts=None,
trials=5,
jobs=1,
enable_multiresolution=True,
objid=None,
instruments=None,
geo=False,
dpi=600,
transparent=False,
colorbar=False,
contour=[50, 90],
annotate=True,
cmap='cylon',
load_pickle=False):
""" Generate a fits file and sky map from a result
Code adapted from ligo.skymap.tool.ligo_skymap_from_samples and
ligo.skymap.tool.plot_skymap. Note, the use of this additionally
required the installation of ligo.skymap.
Parameters
----------
maxpts: int
Maximum number of samples to use, if None all samples are used
trials: int
Number of trials at each clustering number
jobs: int
Number of multiple threads
enable_multiresolution: bool
Generate a multiresolution HEALPix map (default: True)
objid: str
Event ID to store in FITS header
instruments: str
Name of detectors
geo: bool
Plot in geographic coordinates (lat, lon) instead of RA, Dec
dpi: int
Resolution of figure in fots per inch
transparent: bool
Save image with transparent background
colorbar: bool
Show colorbar
contour: list
List of contour levels to use
annotate: bool
Annotate image with details
cmap: str
Name of the colormap to use
load_pickle: bool, str
If true, load the cached pickle file (default name), or the
pickle-file give as a path.
"""
try:
from astropy.time import Time
from ligo.skymap import io, version, plot, postprocess, bayestar, kde
import healpy as hp
except ImportError as e:
logger.info("Unable to generate skymap: error {}".format(e))
return
check_directory_exists_and_if_not_mkdir(self.outdir)
logger.info('Reading samples for skymap')
data = self.posterior
if maxpts is not None and maxpts < len(data):
logger.info('Taking random subsample of chain')
data = data.sample(maxpts)
default_obj_filename = os.path.join(
self.outdir, '{}_skypost.obj'.format(self.label))
if load_pickle is False:
try:
pts = data[['ra', 'dec', 'luminosity_distance']].values
confidence_levels = kde.Clustered2Plus1DSkyKDE
distance = True
except KeyError:
logger.warning(
"The results file does not contain luminosity_distance")
pts = data[['ra', 'dec']].values
confidence_levels = kde.Clustered2DSkyKDE
distance = False
logger.info('Initialising skymap class')
skypost = confidence_levels(pts, trials=trials, jobs=jobs)
logger.info('Pickling skymap to {}'.format(default_obj_filename))
with open(default_obj_filename, 'wb') as out:
pickle.dump(skypost, out)
else:
if isinstance(load_pickle, str):
obj_filename = load_pickle
else:
obj_filename = default_obj_filename
logger.info('Reading from pickle {}'.format(obj_filename))
with open(obj_filename, 'rb') as file:
skypost = pickle.load(file)
skypost.jobs = jobs
distance = isinstance(skypost, kde.Clustered2Plus1DSkyKDE)
logger.info('Making skymap')
hpmap = skypost.as_healpix()
if not enable_multiresolution:
hpmap = bayestar.rasterize(hpmap)
hpmap.meta.update(io.fits.metadata_for_version_module(version))
hpmap.meta['creator'] = "bilby"
hpmap.meta['origin'] = 'LIGO/Virgo'
hpmap.meta['gps_creation_time'] = Time.now().gps
hpmap.meta['history'] = ""
if objid is not None:
hpmap.meta['objid'] = objid
if instruments:
hpmap.meta['instruments'] = instruments
if distance:
hpmap.meta['distmean'] = np.mean(data['luminosity_distance'])
hpmap.meta['diststd'] = np.std(data['luminosity_distance'])
try:
time = data['geocent_time']
hpmap.meta['gps_time'] = time.mean()
except KeyError:
logger.warning('Cannot determine the event time from geocent_time')
fits_filename = os.path.join(self.outdir,
"{}_skymap.fits".format(self.label))
logger.info('Saving skymap fits-file to {}'.format(fits_filename))
io.write_sky_map(fits_filename, hpmap, nest=True)
skymap, metadata = io.fits.read_sky_map(fits_filename, nest=None)
nside = hp.npix2nside(len(skymap))
# Convert sky map from probability to probability per square degree.
deg2perpix = hp.nside2pixarea(nside, degrees=True)
probperdeg2 = skymap / deg2perpix
if geo:
obstime = Time(metadata['gps_time'], format='gps').utc.isot
ax = plt.axes(projection='geo degrees mollweide', obstime=obstime)
else:
ax = plt.axes(projection='astro hours mollweide')
ax.grid()
# Plot sky map.
vmax = probperdeg2.max()
img = ax.imshow_hpx((probperdeg2, 'ICRS'),
nested=metadata['nest'],
vmin=0.,
vmax=vmax,
cmap=cmap)
# Add colorbar.
if colorbar:
cb = plot.colorbar(img)
cb.set_label(r'prob. per deg$^2$')
if contour is not None:
confidence_levels = 100 * postprocess.find_greedy_credible_levels(
skymap)
contours = ax.contour_hpx((confidence_levels, 'ICRS'),
nested=metadata['nest'],
colors='k',
linewidths=0.5,
levels=contour)
fmt = r'%g\%%' if rcParams['text.usetex'] else '%g%%'
plt.clabel(contours, fmt=fmt, fontsize=6, inline=True)
# Add continents.
if geo:
geojson_filename = os.path.join(os.path.dirname(plot.__file__),
'ne_simplified_coastline.json')
with open(geojson_filename, 'r') as geojson_file:
geoms = json.load(geojson_file)['geometries']
verts = [
coord for geom in geoms for coord in zip(*geom['coordinates'])
]
plt.plot(*verts,
color='0.5',
linewidth=0.5,
transform=ax.get_transform('world'))
# Add a white outline to all text to make it stand out from the background.
plot.outline_text(ax)
if annotate:
text = []
try:
objid = metadata['objid']
except KeyError:
pass
else:
text.append('event ID: {}'.format(objid))
if contour:
pp = np.round(contour).astype(int)
ii = np.round(
np.searchsorted(np.sort(confidence_levels), contour) *
deg2perpix).astype(int)
for i, p in zip(ii, pp):
text.append(u'{:d}% area: {:d} deg$^2$'.format(p, i))
ax.text(1, 1, '\n'.join(text), transform=ax.transAxes, ha='right')
filename = os.path.join(self.outdir,
"{}_skymap.png".format(self.label))
logger.info("Generating 2D projected skymap to {}".format(filename))
safe_save_figure(fig=plt.gcf(), filename=filename, dpi=dpi)
