num::structures::debug::verify_laplacian_structure

Defined in header <structures/debug.hpp>

template <class Mat>
void verify_laplacian_structure(
    const Mat &L, double tol = 1e-9,
    std::source_location loc = std::source_location::current());

Verify the structure of a graph Laplacian \(\Delta = D - W\): symmetric with \(\Delta \mathbf{1} = 0\). That null space makes it law::psd, not law::spd.

Dense or CSR; CSR visits only stored entries.