healpy.pixelfunc.ang2pix¶
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healpy.pixelfunc.
ang2pix
(nside, theta, phi, nest=False, lonlat=False)¶ ang2pix : nside,theta[rad],phi[rad],nest=False,lonlat=False -> ipix (default:RING)
Parameters: - nside : int, scalar or array-like
The healpix nside parameter, must be a power of 2, less than 2**30
- theta, phi : float, scalars or array-like
Angular coordinates of a point on the sphere
- nest : bool, optional
if True, assume NESTED pixel ordering, otherwise, RING pixel ordering
- lonlat : bool
If True, input angles are assumed to be longitude and latitude in degree, otherwise, they are co-latitude and longitude in radians.
Returns: - pix : int or array of int
The healpix pixel numbers. Scalar if all input are scalar, array otherwise. Usual numpy broadcasting rules apply.
Examples
>>> import healpy as hp >>> hp.ang2pix(16, np.pi/2, 0) 1440
>>> hp.ang2pix(16, [np.pi/2, np.pi/4, np.pi/2, 0, np.pi], [0., np.pi/4, np.pi/2, 0, 0]) array([1440, 427, 1520, 0, 3068])
>>> hp.ang2pix(16, np.pi/2, [0, np.pi/2]) array([1440, 1520])
>>> hp.ang2pix([1, 2, 4, 8, 16], np.pi/2, 0) array([ 4, 12, 72, 336, 1440])
>>> hp.ang2pix([1, 2, 4, 8, 16], 0, 0, lonlat=True) array([ 4, 12, 72, 336, 1440])