cngi.image.cont_sub

cont_sub(xds, dv='IMAGE', fitorder=2, chans=None, linename='LINE', contname='CONTINUUM', compute=False)[source]

Continuum subtraction of an image cube

Perform a polynomial baseline fit to the specified channels from an image and subtract it from all channels

Parameters

  • xds (xarray.core.dataset.Dataset) – image xarray dataset

  • dv (str) – name of data_var in xds to polynomal fit. Default is ‘IMAGE’

  • chans (array of int) – Spectral channels to use for fitting a polynomial to determine continuum. Default is None, use all channels.

  • fitorder (int) – Order of polynomial to fit to the specified spectral channels to determine the continuum. Default is 2.

  • linename (str) – dataset variable name for output: name of image to which to save the result of subtracting the computed continuum from the input image. overwrites if already present. Default is ‘LINE’

  • contname (str) – dataset variable name for output：the computed continuum image. overwrites if already present. Default is ‘CONTINUUM’

  • compute (bool) – execute the DAG to compute the fit error. Default False returns lazy DAG (error can then be retrieved via xds.<name>.<key>.values)

Returns

output Image

Return type

xarray.core.dataset.Dataset