get_sturm_count_ldl()

int stan::math::internal::get_sturm_count_ldl ( const VectorXdd &  l, const VectorXdd &  d, const double_d  shift  )

inline

Calculates Sturm count of a LDL decomposition of a tridiagonal matrix - number of eigenvalues larger or equal to shift.

Uses stqds - calculation of shifted LDL decomposition algorithm and counts number of positive elements in D.

Parameters

l	Subdiagonal of L.
d	Diagonal of D.
shift	Shift.

Returns

Sturm count.

Definition at line 139 of file mrrr.hpp.