`scipy.fftpack._helper:rfftfreq`

source: /scipy/fftpack/_helper.py :11

Signature

def rfftfreq ( n , d = 1.0 )

Summary

DFT sample frequencies (for usage with rfft, irfft).

Extended Summary

The returned float array contains the frequency bins in cycles/unit (with zero at the start) given a window length n and a sample spacing d:

f = [0,1,1,2,2,...,n/2-1,n/2-1,n/2]/(d*n)   if n is even
f = [0,1,1,2,2,...,n/2-1,n/2-1,n/2,n/2]/(d*n)   if n is odd

Parameters

n : int: Window length.
d : scalar, optional: Sample spacing. Default is 1.

Returns

out : ndarray: The array of length n, containing the sample frequencies.

Examples

import numpy as np
from scipy import fftpack
sig = np.array([-2, 8, 6, 4, 1, 0, 3, 5], dtype=float)
sig_fft = fftpack.rfft(sig)
n = sig_fft.size
timestep = 0.1
freq = fftpack.rfftfreq(n, d=timestep)

✓

freq

✗

Aliases

scipy.fftpack.rfftfreq

Referenced by

This package

scipy.fft._helper:rfftfreq