function x = cs_lsolve (L,b) %#ok %CS_LSOLVE solve a sparse lower triangular system L*x=b. % x = cs_lsolve(L,b) computes x = L\b, L must be lower triangular with a % zero-free diagonal. b must be a column vector. x is full if b is full. % If b is sparse, x is sparse but the nonzero pattern of x is NOT sorted (it % is returned in topological order). % % Example: % Prob = ssget ('HB/bcsstk01') ; L = cs_chol (Prob.A) ; n = size (L,1) ; % b = rand (n,1) ; x = cs_lsolve (L,b) ; norm (L*x-b) % % See also CS_LTSOLVE, CS_USOLVE, CS_UTSOLVE, MLDIVIDE. % CXSparse, Copyright (c) 2006-2022, Timothy A. Davis. All Rights Reserved. % SPDX-License-Identifier: LGPL-2.1+ error ('cs_lsolve mexFunction not found') ;