healpy.pixelfunc.pix2ang

healpy.pixelfunc.pix2ang(nside, ipix, nest=False)

pix2ang : nside,ipix,nest=False -> theta[rad],phi[rad] (default RING)

Parameters:

nside : int or array-like

The healpix nside parameter, must be a power of 2, less than 2**30

ipix : int or array-like

Pixel indices

nest : bool, optional

if True, assume NESTED pixel ordering, otherwise, RING pixel ordering

Returns:

theta, phi : float, scalar or array-like

The angular coordinates corresponding to ipix. Scalar if all input are scalar, array otherwise. Usual numpy broadcasting rules apply.

See also

ang2pix, vec2pix, pix2vec

Examples

>>> import healpy as hp
>>> hp.pix2ang(16, 1440)
(1.5291175943723188, 0.0)

>>> hp.pix2ang(16, [1440,  427, 1520,    0, 3068])
(array([ 1.52911759,  0.78550497,  1.57079633,  0.05103658,  3.09055608]), array([ 0.        ,  0.78539816,  1.61988371,  0.78539816,  0.78539816]))

>>> hp.pix2ang([1, 2, 4, 8], 11)
(array([ 2.30052398,  0.84106867,  0.41113786,  0.2044802 ]), array([ 5.49778714,  5.89048623,  5.89048623,  5.89048623]))