aspcore.fouriertransform.dft.rdft_mat

aspcore.fouriertransform.dft.rdft_mat(dft_len: int, num_freqs_removed_low=0)

DFT matrix corresponding to the real DFT.

Parameters:

• dft_len (int) – Length of the DFT.

• num_freqs_removed_low (int) – Number of frequencies to remove.

Returns:

F – DFT matrix with the first num_to_remove frequencies removed.

Return type:

np.ndarray of shape (L/2 + 1 - num_freqs_removed_low, L)

Notes

The matrix represents the forward transform such that F @ a = rfft(a). Note that the matrix is not square, so the inverse transform is not the hermitian transpose of the forward transform.