cos_simd

scirs2_core::ndarray_ext::elementwise

Function cos_simd 

Source 
pub fn cos_simd<F>(x: &ArrayView1<'_, F>) -> Array1<F>
where
    F: Float + SimdUnifiedOps,
Expand description

Compute the cosine of each element (SIMD-accelerated).

Computes cos(x) for each element in the array.

§Arguments

  • x - Input 1D array (angles in radians)

§Returns

Array1<F> with the same length as input, with cosine values.

§Performance

  • Auto-vectorization: Compiler optimizations provide excellent performance
  • Speedup: 2-4x on large arrays via auto-vectorization

§Mathematical Definition

cos(x) = adjacent/hypotenuse in a right triangle
Periodic with period 2π: cos(x + 2π) = cos(x)
Range: [-1, 1]

§Examples

use scirs2_core::ndarray::array;
use scirs2_core::ndarray_ext::elementwise::cos_simd;
use std::f64::consts::PI;

let x = array![0.0_f64, PI/3.0, PI/2.0, PI];
let result = cos_simd(&x.view());

// cos(0) = 1, cos(π/2) ≈ 0, cos(π) = -1

§Edge Cases

  • Empty array: Returns empty array
  • Zero: cos(0) = 1
  • NaN: Returns NaN (preserves NaN)
  • Infinity: Returns NaN (undefined for infinity)

§Applications

  • Computer Vision: Rotation matrices, coordinate transformations
  • Signal Processing: Fourier transforms, filtering
  • Path Planning: Dubins curves, trajectory optimization
  • Geometry: Circle parametrization, spherical coordinates
  • Neural Networks: Positional encoding (transformers)