fn compute_laplacian(
f: &[f64],
mask: &[u8],
nx: usize,
ny: usize,
nz: usize,
vsx: f64,
vsy: f64,
vsz: f64,
) -> Vec<f64>Expand description
Compute Laplacian of a 3D field using mask-adaptive finite differences
Matches MATLAB’s lap1_mex.c: uses central differences where both neighbors are in the mask, forward/backward one-sided stencils near mask boundaries, and zero contribution where neither neighbor is in the mask.