qspec.doppler_3d  (  k ,  v ,  return_frame = 'atom' ,  axis = -1  )[source]

Parameters:

karray_like

The k-wave-3-vector of light (arb. units).

varray_like

The velocity 3-vector (m/s).

return_frameNone

The coordinate system in which the frequency is returned. Can be either 'atom' or 'lab'.

axisNone

The axis along which the vector components are aligned.

Returns:

outarray_like

the Doppler-shifted k-wave-4-vector in either the rest frame of the atom or the laboratory frame ([k]).

Raises:

ValueError

rest_frame must be either 'atom' or 'lab'. The shapes of k and v must be compatible.