std_simd

scirs2_core::ndarray_ext::reduction

Function std_simd 

Source 
pub fn std_simd<F>(x: &ArrayView1<'_, F>, ddof: usize) -> Option<F>
where
    F: Float + SimdUnifiedOps,
Expand description

Compute the standard deviation of a 1D array with SIMD acceleration.

This function computes the square root of the variance using SIMD-accelerated variance computation.

§Arguments

  • x - Input 1D array
  • ddof - Delta degrees of freedom (0 for population std, 1 for sample std)

§Returns

  • Some(std) - The standard deviation of the array
  • None - If the array is empty or has insufficient data (length <= ddof)

§Performance

  • f32: ~2-3x faster than scalar for arrays > 1000 elements
  • f64: ~2-3x faster than scalar for arrays > 1000 elements
  • Uses SIMD variance followed by sqrt

§Examples

use scirs2_core::ndarray::array;
use scirs2_core::ndarray_ext::reduction::std_simd;

let x = array![1.0f64, 2.0, 3.0, 4.0, 5.0];
let std = std_simd(&x.view(), 1).unwrap(); // Sample std (ddof=1)
assert!((std - 1.5811388300841898).abs() < 1e-10);