pixelfunc – Pixelisation related functions¶

conversion from/to sky coordinates¶

pix2ang(nside, ipix[, nest, lonlat])

pix2ang : nside,ipix,nest=False,lonlat=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, lonlat])

ang2pix : nside,theta[rad],phi[rad],nest=False,lonlat=False -> ipix (default:RING)

vec2pix(nside, x, y, z[, nest])

vec2pix : nside,x,y,z,nest=False -> ipix (default:RING)

vec2ang(vectors[, lonlat])

vec2ang: vectors [x, y, z] -> theta[rad], phi[rad]

ang2vec(theta, phi[, lonlat])

ang2vec : convert angles to 3D position vector

get_all_neighbours(nside, theta[, phi, ...])

Return the 8 nearest pixels.

get_interp_weights(nside, theta[, phi, ...])

Return the 4 closest pixels on the two rings above and below the location and corresponding weights.

get_interp_val(m, theta, phi[, nest, lonlat])

Return the bi-linear interpolation value of map(s) using 4 nearest neighbours.

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(map_in[, inp, out, r2n, n2r])

Reorder a healpix map from RING/NESTED ordering to NESTED/RING

nside/npix/resolution¶

nside2npix(nside)

Give the number of pixels for the given nside.

npix2nside(npix)

Give the nside parameter for the given number of pixels.

nside2order(nside)

Give the resolution order for a given nside.

order2nside(order)

Give the nside parameter for the given resolution order.

nside2resol(nside[, arcmin])

Give approximate resolution (pixel size in radian or arcmin) for nside.

nside2pixarea(nside[, degrees])

Give pixel area given nside in square radians or square degrees.

max_pixrad(nside[, degrees])

Maximum angular distance between any pixel center and its corners

isnsideok(nside[, nest])

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(map_in, nside_out[, pess, ...])

Upgrade or degrade resolution of a map (or list of maps).

Masking pixels¶

UNSEEN

Special value used 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, lonlat])

Return the bi-linear interpolation value of map(s) using 4 nearest neighbours.

healpy

Navigation

  • healpy tutorial
  • Other tutorials
  • Installation procedure for Healpy
  • pixelfunc – Pixelisation related functions
    • conversion from/to sky coordinates
    • conversion between NESTED and RING schemes
    • nside/npix/resolution
    • Masking pixels
    • Map data manipulation
  • sphtfunc – Spherical harmonic transforms
  • visufunc – Visualisation
  • newvisufunc – Experimental visualisation
  • fitsfunc – FITS file related functions
  • Pixel querying routines
  • rotator – Rotation and geometry functions
  • projector – Spherical projections
  • zoomtool – Interactive visualisation
  • Line integral convolution
  • Other functions
  • Licenses

Related Topics

  • Documentation overview
    • Previous: Installation procedure for Healpy
    • Next: healpy.pixelfunc.pix2ang
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