def test_rebin_coord_transform():
x_grid, y_grid, ra_at_xy_0, dec_at_xy_0, x_at_radec_0, y_at_radec_0, Mpix2coord, Mcoord2pix = util.make_grid_with_coordtransform(numPix=3, deltapix=0.03, subgrid_res=1)
x_grid, y_grid, ra_at_xy_0_re, dec_at_xy_0_re, x_at_radec_0_re, y_at_radec_0_re, Mpix2coord_re, Mcoord2pix_re = util.make_grid_with_coordtransform(numPix=1, deltapix=0.09, subgrid_res=1)
ra_at_xy_0_resized, dec_at_xy_0_resized, x_at_radec_0_resized, y_at_radec_0_resized, Mpix2coord_resized, Mcoord2pix_resized = image_util.rebin_coord_transform(3, x_at_radec_0, y_at_radec_0, Mpix2coord, Mcoord2pix)
assert ra_at_xy_0_resized == ra_at_xy_0_re
assert dec_at_xy_0_resized == dec_at_xy_0_re
assert x_at_radec_0_resized == x_at_radec_0_re
assert y_at_radec_0_resized == y_at_radec_0_re
npt.assert_almost_equal(Mcoord2pix_resized[0][0], Mcoord2pix_re[0][0], decimal=8)
npt.assert_almost_equal(Mpix2coord_re[0][0], Mpix2coord_resized[0][0], decimal=8)
x_grid, y_grid, ra_at_xy_0, dec_at_xy_0, x_at_radec_0, y_at_radec_0, Mpix2coord, Mcoord2pix = util.make_grid_with_coordtransform(numPix=100, deltapix=0.05, subgrid_res=1)
x_grid, y_grid, ra_at_xy_0_re, dec_at_xy_0_re, x_at_radec_0_re, y_at_radec_0_re, Mpix2coord_re, Mcoord2pix_re = util.make_grid_with_coordtransform(numPix=50, deltapix=0.1, subgrid_res=1)
ra_at_xy_0_resized, dec_at_xy_0_resized, x_at_radec_0_resized, y_at_radec_0_resized, Mpix2coord_resized, Mcoord2pix_resized = image_util.rebin_coord_transform(2, x_at_radec_0, y_at_radec_0, Mpix2coord, Mcoord2pix)
assert ra_at_xy_0_resized == ra_at_xy_0_re
assert dec_at_xy_0_resized == dec_at_xy_0_re
assert x_at_radec_0_resized == x_at_radec_0_re
assert y_at_radec_0_resized == y_at_radec_0_re
npt.assert_almost_equal(Mcoord2pix_resized[0][0], Mcoord2pix_re[0][0], decimal=8)
npt.assert_almost_equal(Mpix2coord_re[0][0], Mpix2coord_resized[0][0], decimal=8)
x_grid, y_grid, ra_at_xy_0, dec_at_xy_0, x_at_radec_0, y_at_radec_0, Mpix2coord, Mcoord2pix = util.make_grid_with_coordtransform(numPix=99, deltapix=0.1, subgrid_res=1)
x_grid, y_grid, ra_at_xy_0_re, dec_at_xy_0_re, x_at_radec_0_re, y_at_radec_0_re, Mpix2coord_re, Mcoord2pix_re = util.make_grid_with_coordtransform(numPix=33, deltapix=0.3, subgrid_res=1)
assert x_at_radec_0 == 49
ra_at_xy_0_resized, dec_at_xy_0_resized, x_at_radec_0_resized, y_at_radec_0_resized, Mpix2coord_resized, Mcoord2pix_resized = image_util.rebin_coord_transform(3, x_at_radec_0, y_at_radec_0, Mpix2coord, Mcoord2pix)
assert x_at_radec_0_resized == 16
npt.assert_almost_equal(ra_at_xy_0_resized, ra_at_xy_0_re, decimal=8)
npt.assert_almost_equal(dec_at_xy_0_resized, dec_at_xy_0_re, decimal=8)
npt.assert_almost_equal(x_at_radec_0_resized, x_at_radec_0_re, decimal=8)
npt.assert_almost_equal(y_at_radec_0_resized, y_at_radec_0_re, decimal=8)
npt.assert_almost_equal(Mcoord2pix_resized[0][0], Mcoord2pix_re[0][0], decimal=8)
npt.assert_almost_equal(Mpix2coord_re[0][0], Mpix2coord_resized[0][0], decimal=8)
x_in, y_in = 10., 10.
ra, dec = util.map_coord2pix(x_in, y_in, ra_at_xy_0, dec_at_xy_0, Mpix2coord)
x_out, y_out = util.map_coord2pix(ra, dec, x_at_radec_0, y_at_radec_0, Mcoord2pix)
assert x_in == x_out
assert y_in == y_out
x_in, y_in = 10., 10.
ra, dec = util.map_coord2pix(x_in, y_in, ra_at_xy_0_resized, dec_at_xy_0_resized, Mpix2coord_resized)
x_out, y_out = util.map_coord2pix(ra, dec, x_at_radec_0_resized, y_at_radec_0_resized, Mcoord2pix_resized)
assert x_in == x_out
assert y_in == y_out
def map_pix2coord(self, x_pos, y_pos):
"""
:param x_pos: pixel position
:param y_pos: pixel position
:return: (ra, dec) coordinates of pixel position (x_pos, y_pos)
"""
return util.map_coord2pix(x_pos, y_pos, self._ra_at_xy_0,
self._dec_at_xy_0, self._Mpix2a)
def map_pix2coord(self, x, y):
"""
maps the (x,y) pixel coordinates of the image into the system coordinates
:param x: pixel coordinate (can be 1d numpy array), defined in the center of the pixel
:param y: pixel coordinate (can be 1d numpy array), defined in the center of the pixel
:return: relative (RA, DEC) coordinates of the system
"""
return util.map_coord2pix(x, y, self._ra_at_xy_0, self._dec_at_xy_0, self._Mpix2a)
def map_coord2pix(self, ra, dec):
"""
:param ra: ra coordinates, relative
:param dec: dec coordinates, relative
:return: (x, y) pixel position of coordinate (ra, dec)
"""
return util.map_coord2pix(ra, dec, self._x_at_radec_0,
self._y_at_radec_0, self._Ma2pix)
def map_coord2pix(self, ra, dec):
"""
maps the (ra,dec) coordinates of the system into the pixel coordinate of the image
:param ra: relative RA coordinate as defined by the coordinate frame
:param dec: relative DEC coordinate as defined by the coordinate frame
:return: (x, y) pixel coordinates
"""
return util.map_coord2pix(ra, dec, self._x_at_radec_0, self._y_at_radec_0, self._Ma2pix)
def test_grid_with_coords():
numPix = 11
deltaPix = 1.
x_grid, y_grid, ra_at_xy_0, dec_at_xy_0, x_at_radec_0, y_at_radec_0, Mpix2coord, Mcoord2pix = Util.make_grid_with_coordtransform(
numPix, deltaPix, subgrid_res=1, left_lower=False)
ra = 0
dec = 0
x, y = Util.map_coord2pix(ra, dec, x_at_radec_0, y_at_radec_0, Mcoord2pix)
assert x == 5
assert y == 5
numPix = 11
deltaPix = .1
x_grid, y_grid, ra_at_xy_0, dec_at_xy_0, x_at_radec_0, y_at_radec_0, Mpix2coord, Mcoord2pix = Util.make_grid_with_coordtransform(
numPix, deltaPix, subgrid_res=1, left_lower=False)
ra = 0
dec = 0
x, y = Util.map_coord2pix(ra, dec, x_at_radec_0, y_at_radec_0, Mcoord2pix)
assert x == 5
assert y == 5
numPix = 11
deltaPix = 1.
x_grid, y_grid, ra_at_xy_0, dec_at_xy_0, x_at_radec_0, y_at_radec_0, Mpix2coord, Mcoord2pix = Util.make_grid_with_coordtransform(
numPix, deltaPix, subgrid_res=1, left_lower=False)
x_, y_ = 0, 0
ra, dec = Util.map_coord2pix(x_, y_, ra_at_xy_0, dec_at_xy_0, Mpix2coord)
assert ra == -5
assert dec == -5
numPix = 11
deltaPix = .1
x_grid, y_grid, ra_at_xy_0, dec_at_xy_0, x_at_radec_0, y_at_radec_0, Mpix2coord, Mcoord2pix = Util.make_grid_with_coordtransform(
numPix, deltaPix, subgrid_res=1, left_lower=False)
x_, y_ = 0, 0
ra, dec = Util.map_coord2pix(x_, y_, ra_at_xy_0, dec_at_xy_0, Mpix2coord)
assert ra == -.5
assert dec == -.5
x__, y__ = Util.map_coord2pix(ra, dec, x_at_radec_0, y_at_radec_0,
Mcoord2pix)
assert x__ == x_
assert y__ == y_
def test_map_coord2pix():
ra = 0
dec = 0
x_0 = 1
y_0 = -1
M = np.array([[1, 0], [0, 1]])
x, y = util.map_coord2pix(ra, dec, x_0, y_0, M)
assert x == 1
assert y == -1
ra = [0, 1, 2]
dec = [0, 2, 1]
x, y = util.map_coord2pix(ra, dec, x_0, y_0, M)
assert x[0] == 1
assert y[0] == -1
assert x[1] == 2
M = np.array([[0, 1], [1, 0]])
x, y = util.map_coord2pix(ra, dec, x_0, y_0, M)
assert x[1] == 3
assert y[1] == 0
def __init__(self, transform_pix2angle, ra_at_xy_0, dec_at_xy_0):
"""
initialize the coordinate-to-pixel transform and their inverse
:param transform_pix2angle: 2x2 matrix, mapping of pixel to coordinate
:param ra_at_xy_0: ra coordinate at pixel (0,0)
:param dec_at_xy_0: dec coordinate at pixel (0,0)
"""
self._Mpix2a = transform_pix2angle
self._Ma2pix = linalg.inv(self._Mpix2a)
self._ra_at_xy_0 = ra_at_xy_0
self._dec_at_xy_0 = dec_at_xy_0
self._x_at_radec_0, self._y_at_radec_0 = util.map_coord2pix(-self._ra_at_xy_0, -self._dec_at_xy_0, 0, 0, self._Ma2pix)
def shift_coordinate_grid(self, x_shift, y_shift, pixel_unit=False):
"""
shifts the coordinate system
:param x_shif: shift in x (or RA)
:param y_shift: shift in y (or DEC)
:param pixel_unit: bool, if True, units of pixels in input, otherwise RA/DEC
:return: updated data class with change in coordinate system
"""
if pixel_unit is True:
ra_shift, dec_shift = self.map_pix2coord(x_shift, y_shift)
else:
ra_shift, dec_shift = x_shift, y_shift
self._ra_at_xy_0 += ra_shift
self._dec_at_xy_0 += dec_shift
self._x_at_radec_0, self._y_at_radec_0 = util.map_coord2pix(
-self._ra_at_xy_0, -self._dec_at_xy_0, 0, 0, self._Ma2pix)
def rebin_coord_transform(factor, x_at_radec_0, y_at_radec_0, Mpix2coord, Mcoord2pix):
"""
adopt coordinate system and transformation between angular and pixel coordinates of a re-binned image
:param bin_size:
:param ra_0:
:param dec_0:
:param x_0:
:param y_0:
:param Matrix:
:param Matrix_inv:
:return:
"""
factor = int(factor)
Mcoord2pix_resized = Mcoord2pix / factor
Mpix2coord_resized = Mpix2coord * factor
x_at_radec_0_resized = (x_at_radec_0 + 0.5) / factor - 0.5
y_at_radec_0_resized = (y_at_radec_0 + 0.5) / factor - 0.5
ra_at_xy_0_resized, dec_at_xy_0_resized = util.map_coord2pix(-x_at_radec_0_resized, -y_at_radec_0_resized, 0, 0, Mpix2coord_resized)
return ra_at_xy_0_resized, dec_at_xy_0_resized, x_at_radec_0_resized, y_at_radec_0_resized, Mpix2coord_resized, Mcoord2pix_resized