reproject.reproject_to_healpix(input_data, coord_system_out, hdu_in=0, order='bilinear', nested=False, nside=128)[source]

Reproject data from a standard projection to a HEALPIX projection.


input_data : str or HDUList or PrimaryHDU or ImageHDU or tuple

The input data to reproject. This can be:

  • The name of a FITS file
  • An HDUList object
  • An image HDU object such as a PrimaryHDU or ImageHDU instance
  • A tuple where the first element is a ndarray and the second element is either a WCS or a Header object

coord_system_out : BaseCoordinateFrame or str

The output coordinate system for the HEALPIX projection

hdu_in : int or str, optional

If input_data is a FITS file or an HDUList instance, specifies the HDU to use.

order : int or str, optional

The order of the interpolation (if mode is set to 'interpolation'). This can be either one of the following strings:

  • ‘nearest-neighbor’
  • ‘bilinear’
  • ‘biquadratic’
  • ‘bicubic’

or an integer. A value of 0 indicates nearest neighbor interpolation.

nested : bool

The order of the healpix_data, either nested (True) or ring (False)

nside : int, optional

The resolution of the HEALPIX projection.


array_new : ndarray

The reprojected array

footprint : ndarray

Footprint of the input array in the output array. Values of 0 indicate no coverage or valid values in the input image, while values of 1 indicate valid values.