`scipy.linalg._flapack:zsysv`

Summary

Solve a @ x = b for a symmetric indefinite a by Bunch-Kaufman factorization (LAPACK zsysv).

a : ndarray: symmetric matrix of shape (n, n).
b : ndarray: Right-hand side(s) of shape (n, nrhs).
lwork : int, optional: Size of the workspace. Default is max(n, 1). Use zsysv_lwork for the optimal value.
lower : int, optional: If nonzero, the lower triangle of a is referenced; otherwise the upper. Default is 0.
overwrite_a : int, optional: If nonzero, a may be overwritten in place. Default is 0.
overwrite_b : int, optional: If nonzero, b may be overwritten in place. Default is 0.

udut : ndarray: The block diagonal D and the multipliers, packed into the triangle.
ipiv : ndarray: Pivot indices describing the interchanges and the 1x1 / 2x2 block structure, 1-based. Pass them on to sytrs/sytri/sycon unchanged.
x : ndarray: Solution of the system.
info : int: 0 on success; if negative, the -info-th argument had an illegal value; if positive, d[info-1, info-1] is exactly zero and the solve failed.