pixelfunc – Pixelisation related functions¶
conversion from/to sky coordinates¶
pix2ang(nside, ipix[, nest]) | pix2ang : nside,ipix,nest=False -> theta[rad],phi[rad] (default RING) |
pix2vec(nside, ipix[, nest]) | pix2vec : nside,ipix,nest=False -> x,y,z (default RING) |
ang2pix(nside, theta, phi[, nest]) | ang2pix : nside,theta[rad],phi[rad],nest=False -> ipix (default:RING) |
vec2pix(nside, x, y, z[, nest]) | vec2pix : nside,x,y,z,nest=False -> ipix (default:RING) |
vec2ang(vectors) | vec2ang: vectors [x, y, z] -> theta[rad], phi[rad] |
ang2vec(theta, phi) | ang2vec : convert angles to 3D position vector |
get_neighbours(nside, theta[, phi, nest]) | Return the 4 nearest pixels and corresponding weights. |
get_all_neighbours(nside, theta[, phi, nest]) | Return the 8 nearest pixels. |
conversion between NESTED and RING schemes¶
nest2ring(nside, ipix) | Convert pixel number from NESTED ordering to RING ordering. |
ring2nest(nside, ipix) | Convert pixel number from RING ordering to NESTED ordering. |
reorder(*args, **kwds) | Reorder an healpix map from RING/NESTED ordering to NESTED/RING |
nside/npix/resolution¶
nside2npix(nside) | Give the number of pixel for the given nside. |
npix2nside(npix) | Give the nside parameter for the given number of pixels. |
nside2resol(nside[, arcmin]) | Give approximate resolution for nside. |
nside2pixarea(nside[, degrees]) | Give pixel area given nside. |
max_pixrad(nside) | Maximum angular distance between any pixel center and its corners |
isnsideok(nside) | Returns True if nside is a valid nside parameter, False otherwise. |
isnpixok(npix) | Return True if npix is a valid value for healpix map size, False otherwise. |
get_map_size(m) | Returns the npix of a given map (implicit or explicit pixelization). |
get_min_valid_nside(npix) | Returns the minimum acceptable nside so that npix <= nside2npix(nside). |
get_nside(m) | Return the nside of the given map. |
maptype(m) | Describe the type of the map (valid, single, sequence of maps). |
ud_grade(*args, **kwds) | Upgrade or degrade resolution of a map (or list of maps). |
Masking pixels¶
UNSEEN | Special Healpix values for masked pixels. |
mask_bad(m[, badval, rtol, atol]) | Returns a bool array with True where m is close to badval. |
mask_good(m[, badval, rtol, atol]) | Returns a bool array with False where m is close to badval. |
ma(m[, badval, rtol, atol, copy]) | Return map as a masked array, with badval pixels masked. |
Map data manipulation¶
fit_dipole(m[, nest, bad, gal_cut]) | Fit a dipole and a monopole to the map, excluding bad pixels. |
fit_monopole(m[, nest, bad, gal_cut]) | Fit a monopole to the map, excluding unseen pixels. |
remove_dipole(m[, nest, bad, gal_cut, ...]) | Fit and subtract the dipole and the monopole from the given map m. |
remove_monopole(m[, nest, bad, gal_cut, ...]) | Fit and subtract the monopole from the given map m. |
get_interp_val(m, theta, phi[, nest]) | Return the bi-linear interpolation value of a map using 4 nearest neighbours. |