`scipy.linalg._flapack:dgttrf`

Signature

def dgttrf(dl, d, du, overwrite_dl = 0, overwrite_d = 0, overwrite_du = 0)

Compute the LU factorization of a tridiagonal matrix with partial pivoting (LAPACK dgttrf).

dl : ndarray: Subdiagonal elements, length n - 1.
d : ndarray: Diagonal elements, length n.
du : ndarray: Superdiagonal elements, length n - 1.
overwrite_dl : int, optional: If nonzero, dl may be overwritten in place. Default is 0.
overwrite_d : int, optional: If nonzero, d may be overwritten in place. Default is 0.
overwrite_du : int, optional: If nonzero, du may be overwritten in place. Default is 0.

dl : ndarray: Multipliers defining L.
d : ndarray: Diagonal of U.
du : ndarray: First superdiagonal of U.
du2 : ndarray: Second superdiagonal of U, length n - 2.
ipiv : ndarray: Pivot indices, 1-based -- unlike getrf, which returns them 0-based. gttrs, gtcon and gtsvx take them exactly as returned.
info : int: 0 on success; if negative, the -info-th argument had an illegal value; if positive, u[info-1, info-1] is exactly zero and the factor is singular.