shiyan54.m

matlab讲义

n=100;b=[1:n]';
a1=sparse(1:n,1:n,4,n,n);
a2=sparse(2:n,1:n-1,1,n,n);
a=a1+a2+a2';
tic;x=a\b;t1=toc
aa=full(a);
tic;xx=aa\b;t2=toc
y=sum(x)
yy=sum(xx)