1function x = cs_utsolve (U,b) %#ok 2%CS_UTSOLVE solve a sparse lower triangular system U'*x=b. 3% x = cs_utsolve(U,b) computes x = U'\b, U must be upper triangular with a 4% zero-free diagonal. b must be a full vector. 5% 6% Example: 7% Prob = ssget ('HB/arc130') ; A = Prob.A ; n = size (A,1) ; 8% b = rand (n,1); 9% [L U p q] = cs_lu (A) ; 10% x = cs_ltsolve (L, cs_utsolve (U, b(q))) ; % x = L' \ (U' \ b(q)) ; 11% x (p) = x ; 12% norm (A'*x-b) 13% 14% See also CS_LSOLVE, CS_LTSOLVE, CS_USOLVE, MLDIVIDE. 15 16% Copyright 2006-2012, Timothy A. Davis, http://www.suitesparse.com 17 18error ('cs_utsolve mexFunction not found') ; 19