def __init__ (self, path, mode):
try:
from pyrap.images import image
except ImportError:
raise UnsupportedError ('cannot open CASAcore images in Pyrap mode without '
'the Python module "pyrap.images"')
super (PyrapImage, self).__init__ (path, mode)
# no mode specifiable
self._handle = image (path)
allinfo = self._handle.info ()
self.units = maybelower (allinfo.get ('unit'))
self.shape = np.asarray (self._handle.shape (), dtype=np.int)
self.axdescs = []
if 'coordinates' in allinfo:
pc = allinfo['coordinates'].get ('pointingcenter')
# initial=True signifies that the pointing center information
# hasn't actually been initialized.
if pc is not None and not pc['initial']:
# This bit of info doesn't have any metadata about units or
# whatever; appears to be fixed as RA/Dec in radians.
self.pclat = pc['value'][1]
self.pclon = pc['value'][0]
ii = self._handle.imageinfo ()
if 'restoringbeam' in ii:
self.bmaj = _pyrap_convert (ii['restoringbeam']['major'], 'rad')
self.bmin = _pyrap_convert (ii['restoringbeam']['minor'], 'rad')
self.bpa = _pyrap_convert (ii['restoringbeam']['positionangle'], 'rad')
# Make sure that angular units are always measured in radians,
# because anything else is ridiculous.
from pyrap.quanta import quantity
self._wcscale = wcscale = np.ones (self.shape.size)
c = self._handle.coordinates ()
radian = quantity (1., 'rad')
for item in c.get_axes ():
if isinstance (item, six.string_types):
self.axdescs.append (item.replace (' ', '_'))
else:
for subitem in item:
self.axdescs.append (subitem.replace (' ', '_'))
def getconversion (text):
q = quantity (1., text)
if q.conforms (radian):
return q.get_value ('rad')
return 1
i = 0
for item in c.get_unit ():
if isinstance (item, six.string_types):
wcscale[i] = getconversion (item)
i += 1
elif len (item) == 0:
wcscale[i] = 1 # null unit
i += 1
else:
for subitem in item:
wcscale[i] = getconversion (subitem)
i += 1
# Figure out which axes are lat/long/spec. We have some
# paranoia code the give up in case there are multiple axes
# that appear to be of the same type. This stuff could
# be cleaned up.
lat = lon = spec = -1
try:
logspecidx = c.get_names ().index ('spectral')
except ValueError:
specaxname = None
else:
specaxname = c.get_axes ()[logspecidx]
for i, name in enumerate (self.axdescs):
# These symbolic direction names obtained from
# casacore/coordinates/Coordinates/DirectionCoordinate.cc
# Would be nice to have a better system for determining
# this a la what wcslib provides.
if name == specaxname:
spec = i
elif name in ('Right_Ascension', 'Hour_Angle', 'Longitude'):
if lon == -1:
lon = i
else:
lon = -2
elif name in ('Declination', 'Latitude'):
if lat == -1:
lat = i
else:
lat = -2
if lat >= 0:
self._latax = lat
if lon >= 0:
self._lonax = lon
if spec >= 0:
self._specax = spec
# Phew, that was gross.
if self._specax is not None:
sd = c.get_coordinate ('spectral').dict ()
wi = sd.get ('wcs')
if wi is not None:
try:
from mirtask._miriad_c import mirwcs_compute_freq
except ImportError:
pass
else:
spectype = wi['ctype'].replace ('\x00', '')[:4]
restfreq = sd.get ('restfreq', 0.)
specval = self.toworld (0.5 * (self.shape - 1))[self._specax]
self.charfreq = mirwcs_compute_freq (spectype, specval, restfreq) * 1e-9
# TODO: any unit weirdness or whatever here?
self.mjd = c.get_obsdate ()['m0']['value']
def __init__(self, path, mode):
try:
from pyrap.images import image
except ImportError:
raise UnsupportedError(
'cannot open CASAcore images in Pyrap mode without '
'the Python module "pyrap.images"')
super(PyrapImage, self).__init__(path, mode)
# no mode specifiable
self._handle = image(path)
allinfo = self._handle.info()
self.units = maybelower(allinfo.get('unit'))
self.shape = np.asarray(self._handle.shape(), dtype=np.int)
self.axdescs = []
if 'coordinates' in allinfo:
pc = allinfo['coordinates'].get('pointingcenter')
# initial=True signifies that the pointing center information
# hasn't actually been initialized.
if pc is not None and not pc['initial']:
# This bit of info doesn't have any metadata about units or
# whatever; appears to be fixed as RA/Dec in radians.
self.pclat = pc['value'][1]
self.pclon = pc['value'][0]
ii = self._handle.imageinfo()
if 'restoringbeam' in ii:
self.bmaj = _pyrap_convert(ii['restoringbeam']['major'], 'rad')
self.bmin = _pyrap_convert(ii['restoringbeam']['minor'], 'rad')
self.bpa = _pyrap_convert(ii['restoringbeam']['positionangle'],
'rad')
# Make sure that angular units are always measured in radians,
# because anything else is ridiculous.
from pyrap.quanta import quantity
self._wcscale = wcscale = np.ones(self.shape.size)
c = self._handle.coordinates()
radian = quantity(1., 'rad')
for item in c.get_axes():
if isinstance(item, six.string_types):
self.axdescs.append(item.replace(' ', '_'))
else:
for subitem in item:
self.axdescs.append(subitem.replace(' ', '_'))
def getconversion(text):
q = quantity(1., text)
if q.conforms(radian):
return q.get_value('rad')
return 1
i = 0
for item in c.get_unit():
if isinstance(item, six.string_types):
wcscale[i] = getconversion(item)
i += 1
elif len(item) == 0:
wcscale[i] = 1 # null unit
i += 1
else:
for subitem in item:
wcscale[i] = getconversion(subitem)
i += 1
# Figure out which axes are lat/long/spec. We have some
# paranoia code the give up in case there are multiple axes
# that appear to be of the same type. This stuff could
# be cleaned up.
lat = lon = spec = -1
try:
logspecidx = c.get_names().index('spectral')
except ValueError:
specaxname = None
else:
specaxname = c.get_axes()[logspecidx]
for i, name in enumerate(self.axdescs):
# These symbolic direction names obtained from
# casacore/coordinates/Coordinates/DirectionCoordinate.cc
# Would be nice to have a better system for determining
# this a la what wcslib provides.
if name == specaxname:
spec = i
elif name in ('Right_Ascension', 'Hour_Angle', 'Longitude'):
if lon == -1:
lon = i
else:
lon = -2
elif name in ('Declination', 'Latitude'):
if lat == -1:
lat = i
else:
lat = -2
if lat >= 0:
self._latax = lat
if lon >= 0:
self._lonax = lon
if spec >= 0:
self._specax = spec
# Phew, that was gross.
if self._specax is not None:
sd = c.get_coordinate('spectral').dict()
wi = sd.get('wcs')
if wi is not None:
try:
from mirtask._miriad_c import mirwcs_compute_freq
except ImportError:
pass
else:
spectype = wi['ctype'].replace('\x00', '')[:4]
restfreq = sd.get('restfreq', 0.)
specval = self.toworld(0.5 *
(self.shape - 1))[self._specax]
self.charfreq = mirwcs_compute_freq(
spectype, specval, restfreq) * 1e-9
# TODO: any unit weirdness or whatever here?
self.mjd = c.get_obsdate()['m0']['value']
def _wcs_get_freq (wcs, specval):
from mirtask._miriad_c import mirwcs_compute_freq
assert wcs.wcs.spec >= 0
spectype = wcs.wcs.ctype[wcs.wcs.spec][:4]
return mirwcs_compute_freq (spectype, specval, wcs.wcs.restfrq) * 1e-9
def _wcs_get_freq(wcs, specval):
from mirtask._miriad_c import mirwcs_compute_freq
assert wcs.wcs.spec >= 0
spectype = wcs.wcs.ctype[wcs.wcs.spec][:4]
return mirwcs_compute_freq(spectype, specval, wcs.wcs.restfrq) * 1e-9
