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function [L,p] = cs_chol (A,drop) %#ok
%CS_CHOL sparse Cholesky factorization.
% L = cs_chol(A) is the same as L = chol(A)', using triu(A).
% [L,p] = cs_chol(A) first orders A with p=cs_amd(A), so that L*L' = A(p,p).
% A second optional input argument controls whether or not numerically zero
% entries are removed from L. cs_chol(A) and cs_chol(A,1) drop them;
% cs_chol(A,0) keeps them. They must be kept for cs_updown to work properly.
%
% Example:
% Prob = ssget ('HB/bcsstk01') ; A = Prob.A ; [L,p] = cs_chol (A) ;
% cspy (A (p,p)) ;
% cspy (L) ;
%
% See also CS_AMD, CS_UPDOWN, CHOL, AMD, SYMAMD.
% CXSparse, Copyright (c) 2006-2022, Timothy A. Davis. All Rights Reserved.
% SPDX-License-Identifier: LGPL-2.1+
error ('cs_chol mexFunction not found') ;
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