`scipy.linalg._flapack:cgtsvx`

Signature

def cgtsvx(dl, d, du, b, fact = N, trans = N, dlf = None, df = None, duf = None, du2 = None, ipiv = None)

Solve a tridiagonal system with condition estimation and error bounds (LAPACK cgtsvx).

dl : ndarray: Subdiagonal elements, length n - 1.
d : ndarray: Diagonal elements, length n.
du : ndarray: Superdiagonal elements, length n - 1.
b : ndarray: Right-hand side(s) of shape (n, nrhs).
fact : str, optional: 'N' to factorize the matrix, 'F' to reuse the dlf, df, duf, du2 and ipiv supplied. Default is 'N'.
trans : str, optional: 'N', 'T' or 'C' for the system, its transpose, or its conjugate transpose. Default is 'N'.
dlf : ndarray, optional: Multipliers of L to reuse when fact='F'; otherwise computed.
df : ndarray, optional: Diagonal of U to reuse when fact='F'; otherwise computed.
duf : ndarray, optional: First superdiagonal of U to reuse when fact='F'; otherwise computed.
du2 : ndarray, optional: Second superdiagonal of U to reuse when fact='F'; otherwise computed.
ipiv : ndarray, optional: Pivot indices to reuse when fact='F', 1-based as gttrf returns them; otherwise computed.

dlf : ndarray: Multipliers defining L.
df : ndarray: Diagonal of U.
duf : ndarray: First superdiagonal of U.
du2 : ndarray: Second superdiagonal of U.
ipiv : ndarray: Pivot indices, 1-based.
x : ndarray: Solution of the system.
rcond : float: Estimate of the reciprocal condition number.
ferr : ndarray: Estimated forward error bound for each solution vector.
berr : ndarray: Componentwise relative backward error of each solution vector.
info : int: 0 on success; if negative, the -info-th argument had an illegal value; if 0 < info <= n, u[info-1, info-1] is exactly zero; if info = n+1, the matrix is singular to working precision and x may be inaccurate.