Projection

class spectral_cube.lower_dimensional_structures.Projection[source]

Bases: spectral_cube.lower_dimensional_structures.LowerDimensionalObject, spectral_cube.base_class.SpatialCoordMixinClass

Attributes Summary

beam

Methods Summary

convolve_to(beam[, convolve]) Convolve the image to a specified beam.
from_hdu(hdu) Return a projection from a FITS HDU.
quicklook([filename, use_aplpy, aplpy_kwargs]) Use APLpy to make a quick-look image of the projection.
reproject(header[, order]) Reproject the image into a new header.
subimage([xlo, xhi, ylo, yhi]) Extract a region spatially.

Attributes Documentation

beam

Methods Documentation

convolve_to(beam, convolve=<function convolve_fft>)[source]

Convolve the image to a specified beam.

Parameters:

beam : radio_beam.Beam

The beam to convolve to

convolve : function

The astropy convolution function to use, either astropy.convolution.convolve or astropy.convolution.convolve_fft
Returns:

proj : Projection

A Projection convolved to the given beam object.
static from_hdu(hdu)[source]

Return a projection from a FITS HDU.

quicklook(filename=None, use_aplpy=True, aplpy_kwargs={})[source]

Use APLpy to make a quick-look image of the projection. This will make the FITSFigure attribute available.

If there are unmatched celestial axes, this will instead show an image without axis labels.

Parameters:

filename : str or Non

Optional - the filename to save the quicklook to.
reproject(header, order='bilinear')[source]

Reproject the image into a new header.

Parameters:

header : astropy.io.fits.Header

A header specifying a cube in valid WCS

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.
subimage(xlo='min', xhi='max', ylo='min', yhi='max')[source]

Extract a region spatially.

Parameters:

[xy]lo/[xy]hi : int or astropy.units.Quantity or min/max

The endpoints to extract. If given as a quantity, will be interpreted as World coordinates. If given as a string or int, will be interpreted as pixel coordinates.