def _map_pixel_coordinates(self, coord0, d0, incl0, pa0):
shape = (self.ref_header["NAXIS2"], self.ref_header["NAXIS1"])
yindices, xindices = np.mgrid[0 : shape[0], 0 : shape[1]]
self.y_indices_flat = yindices.flatten()
self.x_indices_flat = xindices.flatten()
self.ra, self.dec = self.ref_wcs.all_pix2world(self.x_indices_flat, self.y_indices_flat, 0)
coords = SkyCoord(self.ra, self.dec, "icrs", unit="deg")
pixel_R, pixel_PA, sky_radius = galaxy_coords(coords, coord0, pa0, incl0, d0)
self.pixel_R = pixel_R.kpc
self.image_sky_r = sky_radius # arcsec units
self.image_pa = pixel_PA.deg
# Measure position on the sky
# TODO put into galaxy_coords?
delta_ra = coords.ra - coord0.ra
P = Angle(
np.arctan2(
np.sin(delta_ra.rad),
np.cos(coord0.dec.rad) * np.tan(coords.dec.rad) - np.sin(coord0.dec.rad) * np.cos(delta_ra.rad),
),
unit=u.rad,
)
# Reset wrap-around range
s = np.where(P < 0.0)[0]
P[s] = Angle(2.0 * np.pi, unit=u.rad) + P[s]
P -= pa0
s = np.where(P.deg < 0.0)[0]
P[s] += Angle(2.0 * np.pi, unit=u.rad)
self.image_sky_pa = P.deg
def _map_pixel_coordinates(self, coord0, d0, incl0, pa0):
shape = (self.ref_header['NAXIS2'], self.ref_header['NAXIS2'])
yindices, xindices = np.mgrid[0:shape[0], 0:shape[1]]
y_indices_flat = yindices.flatten()
x_indices_flat = xindices.flatten()
ra, dec = self.ref_wcs.all_pix2world(x_indices_flat, y_indices_flat, 0)
coords = SkyCoord(ra, dec, "icrs", unit="deg")
pixel_R, pixel_PA, sky_radius = galaxy_coords(coords,
coord0,
pa0,
incl0,
d0)
self.image_r = pixel_R.kpc.reshape(*shape)
self.image_sky_r = sky_radius.reshape(*shape) # arcsec units
self.image_pa = pixel_PA.deg.reshape(*shape)
# Make an image of position angle on sky
self.image_sky_pa = -1. * np.ones(shape, dtype=np.float)
delta_ra = coords.ra - coord0.ra
P = Angle(np.arctan2(np.sin(delta_ra.rad),
np.cos(coord0.dec.rad) * np.tan(coords.dec.rad)
- np.sin(coord0.dec.rad) * np.cos(delta_ra.rad)),
unit=u.rad)
# Reset wrap-around range
s = np.where(P < 0.)[0]
P[s] = Angle(2. * np.pi, unit=u.rad) + P[s]
P -= pa0
s = np.where(P.deg < 0.)[0]
P[s] += Angle(2. * np.pi, unit=u.rad)
self.image_sky_pa = P.deg.reshape(*shape)
fits.writeto("_sky_pa_image.fits", self.image_sky_pa, clobber=True)