def get_rotated_pixels(shape_source,
wcs_source,
shape_target,
wcs_target,
inverse=False):
""" Given a source geometry (shape_source,wcs_source)
return the pixel positions in the target geometry (shape_target,wcs_target)
if the source geometry were rotated such that its center lies on the center
of the target geometry.
WARNING: Only currently tested for a rotation along declination from one CAR
geometry to another CAR geometry.
"""
from enlib import coordinates
# what are the center coordinates of each geometris
center_source = enmap.pix2sky(shape_source, wcs_source,
(shape_source[0] / 2., shape_source[1] / 2.))
center_target = enmap.pix2sky(shape_target, wcs_target,
(shape_target[0] / 2., shape_target[1] / 2.))
decs, ras = center_source
dect, rat = center_target
# what are the angle coordinates of each pixel in the target geometry
pos_target = enmap.posmap(shape_target, wcs_target)
lra = pos_target[1, :, :].ravel()
ldec = pos_target[0, :, :].ravel()
del pos_target
# recenter the angle coordinates of the target from the target center to the source center
if inverse:
newcoord = coordinates.decenter((lra, ldec), (rat, dect, ras, decs))
else:
newcoord = coordinates.recenter((lra, ldec), (rat, dect, ras, decs))
del lra
del ldec
# reshape these new coordinates into enmap-friendly form
new_pos = np.empty((2, shape_target[0], shape_target[1]))
new_pos[0, :, :] = newcoord[1, :].reshape(shape_target)
new_pos[1, :, :] = newcoord[0, :].reshape(shape_target)
del newcoord
# translate these new coordinates to pixel positions in the target geometry based on the source's wcs
pix_new = enmap.sky2pix(shape_source, wcs_source, new_pos)
return pix_new
def cel2foc(cpos, site, mjd, bore):
baz, bel = bore
hpos = coordinates.transform("cel","hor",cpos,time=mjd,site=site)
fpos = coordinates.recenter(hpos, [baz,bel,0,0])
return fpos
def cel2foc(cpos, site, mjd, bore):
baz, bel = bore
hpos = coordinates.transform("cel", "hor", cpos, time=mjd, site=site)
fpos = coordinates.recenter(hpos, [baz, bel, 0, 0])
return fpos
def foc2cel(fpos, site, mjd, bore):
baz, bel = bore
hpos = coordinates.recenter(fpos, [0,0,baz,bel])
cpos = coordinates.transform("hor","cel",hpos,time=mjd,site=site)
return cpos
def foc2cel(fpos, site, mjd, bore):
baz, bel = bore
hpos = coordinates.recenter(fpos, [0, 0, baz, bel])
cpos = coordinates.transform("hor", "cel", hpos, time=mjd, site=site)
return cpos