def make_wcs(shape, galactic=False):
"""
Create a simple celestial WCS object in either the ICRS or Galactic
coordinate frame.
Parameters
----------
shape : 2-tuple of int
The shape of the 2D array to be used with the output
`~astropy.wcs.WCS` object.
galactic : bool, optional
If `True`, then the output WCS will be in the Galactic
coordinate frame. If `False` (default), then the output WCS
will be in the ICRS coordinate frame.
Returns
-------
wcs : `~astropy.wcs.WCS` object
The world coordinate system (WCS) transformation.
See Also
--------
make_imagehdu
Examples
--------
>>> from photutils.datasets import make_wcs
>>> shape = (100, 100)
>>> wcs = make_wcs(shape)
>>> print(wcs.wcs.crpix) # doctest: +FLOAT_CMP
[50. 50.]
>>> print(wcs.wcs.crval) # doctest: +FLOAT_CMP
[197.8925 -1.36555556]
"""
wcs = WCS(naxis=2)
rho = np.pi / 3.
scale = 0.1 / 3600.
if astropy_version < '3.1':
wcs._naxis1 = shape[1] # nx
wcs._naxis2 = shape[0] # ny
else:
wcs.pixel_shape = shape
wcs.wcs.crpix = [shape[1] / 2, shape[0] / 2] # 1-indexed (x, y)
wcs.wcs.crval = [197.8925, -1.36555556]
wcs.wcs.cunit = ['deg', 'deg']
wcs.wcs.cd = [[-scale * np.cos(rho), scale * np.sin(rho)],
[scale * np.sin(rho), scale * np.cos(rho)]]
if not galactic:
wcs.wcs.radesys = 'ICRS'
wcs.wcs.ctype = ['RA---TAN', 'DEC--TAN']
else:
wcs.wcs.ctype = ['GLON-CAR', 'GLAT-CAR']
return wcs
def make_wcs(shape, galactic=False):
"""
Create a simple celestial WCS object in either the ICRS or Galactic
coordinate frame.
Parameters
----------
shape : 2-tuple of int
The shape of the 2D array to be used with the output
`~astropy.wcs.WCS` object.
galactic : bool, optional
If `True`, then the output WCS will be in the Galactic
coordinate frame. If `False` (default), then the output WCS
will be in the ICRS coordinate frame.
Returns
-------
wcs : `~astropy.wcs.WCS` object
The world coordinate system (WCS) transformation.
See Also
--------
make_imagehdu
Examples
--------
>>> from photutils.datasets import make_wcs
>>> shape = (100, 100)
>>> wcs = make_wcs(shape)
>>> print(wcs.wcs.crpix) # doctest: +FLOAT_CMP
[50. 50.]
>>> print(wcs.wcs.crval) # doctest: +FLOAT_CMP
[197.8925 -1.36555556]
"""
wcs = WCS(naxis=2)
rho = np.pi / 3.
scale = 0.1 / 3600.
if astropy_version < '3.1':
wcs._naxis1 = shape[1] # nx
wcs._naxis2 = shape[0] # ny
else:
wcs.pixel_shape = shape
wcs.wcs.crpix = [shape[1] / 2, shape[0] / 2] # 1-indexed (x, y)
wcs.wcs.crval = [197.8925, -1.36555556]
wcs.wcs.cunit = ['deg', 'deg']
wcs.wcs.cd = [[-scale * np.cos(rho), scale * np.sin(rho)],
[scale * np.sin(rho), scale * np.cos(rho)]]
if not galactic:
wcs.wcs.radesys = 'ICRS'
wcs.wcs.ctype = ['RA---TAN', 'DEC--TAN']
else:
wcs.wcs.ctype = ['GLON-CAR', 'GLAT-CAR']
return wcs
def make_wcs(shape):
"""
Create a simple celestial WCS object.
Parameters
----------
shape : 2-tuple of int
The shape of the 2D array to be used with the output
`~astropy.wcs.WCS` object.
Returns
-------
wcs : `~astropy.wcs.WCS` object
The world coordinate system (WCS) transformation.
See Also
--------
make_imagehdu
Examples
--------
>>> from photutils.datasets import make_wcs
>>> shape = (100, 100)
>>> wcs = make_wcs(shape)
>>> print(wcs.wcs.crpix)
[ 50. 50.]
>>> print(wcs.wcs.crval)
[ 197.8925 -1.36555556]
"""
wcs = WCS(naxis=2)
rho = np.pi / 3.
scale = 0.1 / 3600.
wcs._naxis1 = shape[1] # nx
wcs._naxis2 = shape[0] # ny
wcs.wcs.crpix = [shape[1] / 2, shape[0] / 2] # 1-indexed (x, y)
wcs.wcs.crval = [197.8925, -1.36555556]
wcs.wcs.cunit = ['deg', 'deg']
wcs.wcs.radesys = 'ICRS'
wcs.wcs.cd = [[-scale * np.cos(rho), scale * np.sin(rho)],
[scale * np.sin(rho), scale * np.cos(rho)]]
wcs.wcs.ctype = ['RA---TAN', 'DEC--TAN']
return wcs
def create_wcs(ra, dec, cenchan):
"""Creates a fake WCS header to generate a MWA primary beam response
Arguments:
ra {float} -- Observation pointing direction in degrees
dec {float} -- Observation pointing direction in degrees
cenchan {float} -- Central channel
Returns:
{astropy.wcs.WCS} -- WCS information describing the observation
"""
pixscale = 0.6 / float(cenchan)
# print("pixscale: ", pixscale)
# print("cenchan: ", cenchan)
w = WCS(naxis=2)
w.wcs.crpix = [4000, 4000]
w.wcs.cdelt = np.array([-pixscale, pixscale])
w.wcs.crval = [ra, dec]
w.wcs.ctype = ["RA---SIN", "DEC--SIN"]
w.wcs.cunit = ["deg", "deg"]
w._naxis1 = 8000
w._naxis2 = 8000
return w
wcs = WCS(naxis=2)
wcs.wcs.cdelt = [dra, ddec]
wcs.wcs.crval = [0, 0]
wcs.wcs.ctype = ['RA---CAR', 'DEC--CAR']
wcs.wcs.crpix = [1 + 180 / dra, 1 + 90 / np.fabs(ddec)]
dl, dw_q, dw_u = nmt.synfast_spherical(
-1,
[cltt + nltt, clte + nlte, 0 * cltt, clee + nlee, 0 * clee, clbb + nlbb],
[0, 2],
wcs=wcs)
sl, sw_q, sw_u = nmt.synfast_spherical(-1, [
cltt / (l + 1.)**1.5, 0 * clte, 0 * cltt, clee /
(l + 1.)**1.5, 0 * clee, 0.5 * clee / (l + 1.)**1.5
], [0, 2],
wcs=wcs)
wcs._naxis2, wcs._naxis1 = dl.shape
mask = getmaskapoana_car(wcs, 20., 0.4, dec0=90.)
write_flat_map("mps_car_small.fits", np.array([dl, dw_q, dw_u]), wcs,
["T", "Q", "U"])
write_flat_map("tmp_car_small.fits", np.array([sl, sw_q, sw_u]), wcs,
["T", "Q", "U"])
write_flat_map("msk_car_small.fits", mask, wcs, "mask")
plt.figure()
plt.imshow(dl * mask, interpolation='nearest', origin='lower')
plt.figure()
plt.imshow(dw_q * mask, interpolation='nearest', origin='lower')
plt.figure()
plt.imshow(dw_u * mask, interpolation='nearest', origin='lower')
plt.figure()
