def map_coord2pix(self, ra, dec):
"""
:param ra: ra coordinates, relative
:param dec: dec coordinates, relative
:return: x, y pixel coordinates
"""
x_0, y_0 = self.pixel_at_angle_0
_pix2coord_transform, _coord2pix_transform = self.transforms
x_pos, y_pos = util.map_coord2pix(ra, dec, x_0, y_0,
_coord2pix_transform)
return x_pos, y_pos
def map_pix2coord(self, x_pos, y_pos):
"""
:param x_pos: pixel coordinate
:param y_pos: pixel coordinate
:return: relative ra, dec coordinate
"""
ra_0, dec_0 = self.coord_at_pixel_0
_pix2coord_transform, _coord2pix_transform = self.transforms
ra_pos, dec_pos = util.map_coord2pix(x_pos, y_pos, ra_0, dec_0,
_pix2coord_transform)
return ra_pos, dec_pos
def coord_at_pixel_0(self):
"""
:return: angular coordinate (relative arc sec) (ra_0, dec_0) of (pix_x,pix_y) = (0,0)
"""
#head = self.header
#wcs = pywcs.WCS(head)
x0, y0 = self.pixel_at_angle_0
_pix2coord_transform, _coord2pix_transform = self.transforms
ra_pos, dec_pos = util.map_coord2pix(-x0, -y0, 0, 0,
_pix2coord_transform)
#ra_0, dec_0 = wcs.all_pix2world(self._xmin_c, self._ymin_c, 0)
#cos_dec = np.cos(self.dec / 360 * 2 * np.pi)
#d_ra = (ra_0 - self.ra) * 3600. * cos_dec
#d_dec = (dec_0 - self.dec) * 3600.
#return d_ra, d_dec
return ra_pos, dec_pos