calculate_image_frequency_moments

ska_sdp_func_python.image.taylor_terms.calculate_image_frequency_moments(im: Image, reference_frequency=None, nmoment=1) → Image

Calculate frequency weighted moments of an image cube.

The frequency moments are calculated using:

\[w_k = \left(\left(\nu - \nu_{ref}\right) / \nu_{ref}\right)^k\]

Note that the spectral axis is replaced by a MOMENT axis.

For example, to find the moments and then reconstruct from just the moments:

moment_cube =
    calculate_image_frequency_moments(model_multichannel, nmoment=5)

Parameters:

• im – Image cube

• reference_frequency – Reference frequency (default None uses average)

• nmoment – Number of moments to calculate

Returns:

Moments Image cube