pub fn gradient_1d(ys: &[f64], dx: f64) -> Vec<f64>Expand description
Numerical gradient of uniformly-spaced 1D data.
Given array ys of length n and uniform spacing dx, returns n
gradient values using:
- forward difference at the first point
- central difference at interior points
- backward difference at the last point
This matches NumPy’s np.gradient behaviour for 1D uniform grids.