prev_fast_len

scirs2_fft::helper

Function prev_fast_len 

Source 
pub fn prev_fast_len(target: usize, real: bool) -> usize
Expand description

Find the previous fast size of input data to fft.

Useful for discarding a minimal number of samples before FFT. See next_fast_len for more detail about FFT performance and efficient sizes.

§Arguments

  • target - Length to start searching from
  • real - If true, find the previous fast size for real FFT

§Returns

  • The largest fast length less than or equal to target

§Examples

use scirs2_fft::prev_fast_len;

let n = prev_fast_len(1000, false);
assert!(n <= 1000);