并发循环超过2个变量

Question

在Octave中是否有可能在同一时间内形成两个循环，例如：

(for i=0:10 && j=10:20)
  i;
  j;
  end

Answer 1

如果循环的长度相同，那么是的。不为人所知的是，对于非向量，一个for循环，在列上循环。所以，只要把你的向量放在一个矩阵中，每一个变量一行：

for r = [0:10; 10:20]
  printf ("1st is %2i; 2nd is %2i\n", r(1), r(2));
endfor

返回：

1st is  0; 2nd is 10
1st is  1; 2nd is 11
1st is  2; 2nd is 12
1st is  3; 2nd is 13
1st is  4; 2nd is 14
1st is  5; 2nd is 15
1st is  6; 2nd is 16
1st is  7; 2nd is 17
1st is  8; 2nd is 18
1st is  9; 2nd is 19
1st is 10; 2nd is 20

Answer 2

在Matlab中，您可以对两个大小相同的输入数组使用arrayfun：

>> arrayfun(@(x,y) x+y, 1:10, 10:10:100)
ans =
    11    22    33    44    55    66    77    88    99   110

Answer 3

如果希望它们步进，那么使用一个计数器变量将它们作为数组引用：

j = 0:10;
i = 0:10;
for k = 1:11
    i(k);
    j(k);
end

但是您很可能需要使嵌套的for循环：

for i = 0:10
    for j = 0:10
        i;
        j;
    end
end