From e461df7573c2b7b7e26c965d8cf2d8e175d67378 Mon Sep 17 00:00:00 2001 From: Nguyễn Gia Phong Date: Mon, 16 Dec 2019 21:31:18 +0700 Subject: [usth/MATH2.2] Numerical Methods The future starts now. --- usth/MATH2.2/labwork/3/subst.m | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) create mode 100644 usth/MATH2.2/labwork/3/subst.m (limited to 'usth/MATH2.2/labwork/3/subst.m') diff --git a/usth/MATH2.2/labwork/3/subst.m b/usth/MATH2.2/labwork/3/subst.m new file mode 100644 index 0000000..5c6e783 --- /dev/null +++ b/usth/MATH2.2/labwork/3/subst.m @@ -0,0 +1,17 @@ +function x = subst (aug) + [m n] = size (aug); + x = zeros (m, 1); + if (istril (aug)) + x(m) = aug(1, n) / aug(1, m); + for k = 2 : m + x(k) = (aug(k, n) - aug(k, k+1:m)*x(1:k-1)) / aug(k, k); + end + elseif (istriu (aug)) + x(m) = aug(m, n) / aug(m, m); + for k = m - 1 : -1 : 1 + x(k) = (aug(k, n) - aug(k, k+1:m)*x(k+1:m)) / aug(k, k); + end + else + error ('aug must be a triangular matrix'); + end +end -- cgit 1.4.1