In Reply to: 提示:有關作業二的第二題 posted by Roger Jang on March 11, 1997 at 10:44:42:
同學們如果不熟悉for迴圈和vector運算的寫法,
可以參考下面兩種產生Hilbert矩陣的方法:
每日一字 "Hilbert matrix"
Hilbert matrix is the N by N matrix with elements
which equal to 1/(i+j-1)
for迴圈版本:
FOR I = 1:N,
FOR J = 1:N,
A(I,J) = 1/(I+J-1);
END
END
vector運算版本
J = 1:n;
J = J(ones(n,1),:);
I = J';
E = ones(n,n);
H = E./(I+J-1);
看得用力一點,就會明白vector運算是如何利用
【空間換取時間】了。