标签:blog io ar os for on 2014 log bs
function [P, L, U] = plu(A) % The implementation of PLU Factorization % L is lower triangular and U is upper triangular % P is permutation matrix % Author: Zhenlin Du(Johnsondu) % Email: qlduzhlin@126.com % Time: 2014-11-27 22:00 A = double(A); [m, n] = size(A); L1 = zeros(m, n); L = zeros(m, min(m, n)); U1 = zeros(n, n); U = zeros(min(m, n), n); P = eye(m); % row operation for i = 1: m mval = 0.0; row = i; % find maximum number in current column for k = i : min(i, n) for j = i: m if abs(mval) < abs(A(j, k)) mval = A(j, k); row = j; end end end % if current maximum number is zero % process the next column if mval == 0 continue; end % exchange process, in P, L, U if row ~= i tmp = A(i, :); A(i, :) = A(row, :); A(row, :) = tmp; tmp = P(i, :); P(i, :) = P(row, :); P(row, :) = tmp; tmp = L1(i, :); L1(i, :) = L1(row, :); L1(row, :) = tmp; end for j = i+1 : m ratio = A(j, i) / mval; A(j, :) = A(j, :) - ratio * A(i, :); L1(j, i) = ratio; end end for i = 1: min(m, n) L1(i, i) = 1.0; end for i = 1: m for j = 1: min(m, n) L(i, j) = L1(i, j); end end U1 = A; for i = 1: min(m, n) for j = 1 : n U(i, j) = U1(i, j); end end
PLU decomposition Matlab version
标签:blog io ar os for on 2014 log bs
原文地址:http://blog.csdn.net/zone_programming/article/details/41630339