Module util

Functions

• apply_circulant
  Given the first row circ_matrix of an NxN circulant matrix, say C, return the product C*input.
• apply_circulant_fft
  Use the convolution theorem to calculate the product of the given circulant matrix and the given vector.
• dot_product
  This will throw an error if N = 0 but it’s hard to imagine this case coming up.
• first_row_to_first_col
  Given the first row of a circulant matrix, return the first column.