reproject_from_healpix

reproject.reproject_from_healpix(input_data, output_projection, shape_out=None, hdu_in=1, order='bilinear', nested=None, field=0)

Reproject data from a HEALPIX projection to a standard projection.

Parameters:

input_data : str or TableHDU or BinTableHDU or tuple

The input data to reproject. This can be:

• The name of a HEALPIX FITS file
• A TableHDU or BinTableHDU instance
• A tuple where the first element is a ndarray and the second element is a BaseCoordinateFrame instance or a string alias for a coordinate frame.

output_projection : WCS or Header

The output projection, which can be either a WCS or a Header instance.

shape_out : tuple, optional

If output_projection is a WCS instance, the shape of the output data should be specified separately.

hdu_in : int or str, optional

If input_data is a FITS file, specifies the HDU to use. (the default HDU for HEALPIX data is 1, unlike with image files where it is generally 0)

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’

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

nested : bool, optional

The order of the healpix_data, either nested (True) or ring (False). If a FITS file is passed in, this is determined from the header.

field : int, optional

The column to read from the HEALPIX FITS file. If the fits file is a partial-sky file, field=0 corresponds to the first column after the pixel index column.

Returns:

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.