Bit Reverse

Contains three implementations of a bit reverse copy algorithm for the FFT.

Available Methods:

• bit_reverse_lessefficient

• bit_reverse_standard

• bit_reverse

Dependencies:

• numpy

audiergon.bit_reverse.bit_reverse(arr, convert_to_complex=False)

Bit reversal permutation to make a more efficient FFT using np vectors.

Optimized using NumPy array indexing and vectorisation

Parameters:

• arr (list or numpy.ndarray) – The input signal or sequence to permute.

• convert_to_complex (bool, optional) – If True, casts the result to complex numbers, defaults to False.

Returns:

A vectorized NumPy array reordered via bit-reversal indices.

Return type:

numpy.ndarray

audiergon.bit_reverse.bit_reverse_lessefficient(arr)

Bit reversal permutation on an array to make a more efficient FFT.

Doesn’t use bitwise operations or numpy vectorisation so it is less efficient.

Parameters:

arr (list or numpy.ndarray) – The input signal or sequence to permute.

Returns:

The bit-reversed permuted list.

Return type:

list

audiergon.bit_reverse.bit_reverse_standard(arr, convert_to_complex=False)

Bit reversal permutation on an array to make a more efficient FFT.

Uses standard python lists and optimized bitwise operations.

Parameters:

• arr (list or numpy.ndarray) – The input signal or sequence to permute.

• convert_to_complex (bool, optional) – If True, converts elements to complex numbers, defaults to False.

Returns:

The bit-reversed permuted list.

Return type:

list