def cholesky_banded(ab, overwrite_ab=False, lower=False, check_finite=True):
    if check_finite:
        ab = asarray_chkfinite(ab)
    else:
        ab = asarray(ab)

    pbtrf, = get_lapack_funcs(('pbtrf',), (ab,))
    c, info = pbtrf(ab, lower=lower, overwrite_ab=overwrite_ab)
    if info > 0:
        raise LinAlgError("%d-th leading minor not positive definite" % info)
    if info < 0:
        raise ValueError('illegal value in %d-th argument of internal pbtrf'
                                                                    % -info)
    return c
Cholesky decompose a banded Hermitian positive-definite matrix
dataset/ETHPy150Open scipy/scipy/scipy/linalg/decomp_cholesky.py/cholesky_banded