function L = resymbol (L, A)                                          %#ok
%RESYMBOL recomputes the symbolic Cholesky factorization of the matrix A
%
% Example:
%   L = resymbol (L, A)
%
% Recompute the symbolic Cholesky factorization of the matrix A.  A must
% be symmetric.  Only tril(A) is used.  Entries in L that are not in the
% Cholesky factorization of A are removed from L.  L can be from an LL'
% or LDL' factorization (lchol or ldlchol).  resymbol is useful after a
% series of downdates via ldlupdate or ldlrowmod, since downdates do not
% remove any entries in L.  The numerical values of A are ignored; only
% its nonzero pattern is used.
%
% See also lchol, ldlupdate, ldlrowmod.

 % Copyright 2006-2023, Timothy A. Davis, All Rights Reserved.
 % SPDX-License-Identifier: GPL-2.0+

error ('resymbol not found') ;