# These functions correspond to a standard single-resolution HEALPix implementation
# They are all needed to generalize the standard for multi-resolution maps
# Currently these are trivial wrappers for healpy. These is the only file in
# mhealpy that imports healpy explicitely. The goal with having all of them in
# a single place is to facilitate swapping healpy by some other implementation
# in the future if needed.
import healpy as hp
import numpy as np
MAX_ORDER = 29
MAX_NSIDE = 536870912
UNSEEN = hp.UNSEEN
# Order/npix/nside conversion
[docs]def order2npix(order):
"""
Get the number of pixel for a map of a given order
Args:
order (int or array)
Return:
int or array
"""
return 12*4**np.array(order, dtype=int)
[docs]def nside2order(nside):
return hp.nside2order(nside)
[docs]def order2nside(order):
return hp.order2nside(order)
[docs]def nside2npix(nside):
return hp.nside2npix(nside)
[docs]def npix2nside(npix):
return hp.npix2nside(npix)
[docs]def nside2pixarea(nside):
return hp.nside2pixarea(nside)
# Ang/pix conversion
[docs]def pix2ang(nside, ipix, nest = False, lonlat = False):
return hp.pix2ang(nside, ipix, nest, lonlat = lonlat)
[docs]def pix2vec(nside, ipix, nest = False):
return hp.pix2vec(nside, ipix, nest)
[docs]def ang2pix(nside, theta, phi, nest = False, lonlat = False):
return hp.ang2pix(nside, theta, phi, nest = nest, lonlat = lonlat)
[docs]def vec2pix(nside, x,y,z, nest = False):
return hp.vec2pix(nside, x,y,z, nest)
# Vec/ang conversion
[docs]def vec2ang(vectors):
return hp.vec2ang(vectors)
[docs]def ang2vec(theta, phi, lonlat = False):
return hp.ang2vec(theta, phi, lonlat = lonlat)
# Conversion ring/nest
[docs]def nest2ring(nside, ipix):
return hp.nest2ring(nside, ipix)
[docs]def ring2nest(nside, ipix):
return hp.ring2nest(nside, ipix)
# Convenience methods
[docs]def isnpixok(npix):
return hp.isnpixok(npix)
# Pixel querying
[docs]def get_all_neighbours(nside, theta, phi = None, nest = False, lonlat = False):
return hp.get_all_neighbours(nside, theta, phi, nest = nest, lonlat = lonlat)
[docs]def query_disc(nside, vec, radius, inclusive=False, fact=4, nest=False):
return hp.query_disc(nside, vec, radius, inclusive, fact, nest)
[docs]def query_polygon(nside, vertices, inclusive=False, fact=4, nest=False):
return hp.query_polygon(nside, vertices, inclusive, fact, nest)
[docs]def query_strip(nside, theta1, theta2, inclusive=False, nest=False):
return hp.query_strip(nside, theta1, theta2, inclusive, nest)
[docs]def boundaries(nside, pix, step=1, nest=False):
return hp.boundaries(nside, pix, step, nest)
# Interpolation
[docs]def get_interp_weights(nside, theta, phi=None, nest=False, lonlat = False):
return hp.get_interp_weights(nside, theta, phi, nest, lonlat = lonlat)