数值高斯消去法.rar

function x=gauss(A,b) A=[1, 2.1, 3.6, 7; 8, 1, 5.4, 2; 10, 4.98, 36.6, 90; 5, 0.3, 9.9, 4]; b=[2;2;3;1]; n=length(A); a=[A,b]; for k=1:n-1 maxa=max(abs(a(k:n,k))); if maxa==0 return; end for i=k:n if abs(a(i,k))==maxa y=a(i,k:n+1);a(i,k:n+1)=a(k,k:n+1);a(k,k:n+1)=y; break; end end for i=k+1:n l(i,k)=a(i,k)/a(k,k); a(i,k+1:n+1)=a(i,k+1:n+1)-l(i,k).*a(k,k+1:n+1); end end if a(n,n)==0 return end x(n)=a(n,n+1)/a(n,n); for i=n-1:-1:1 x(i)=(a(i,n+1)-sum(a(i,i+1:n).*x(i+1:n)))/a(i,i); end % ans = % 0.11517855565176 1.00259749438977 0.03180016374228 -0.04787341190607