如何使用逻辑索引替换矩阵元素？

Question

The following is my matrix, 以下是我的矩阵，

coords = [
     1    -1;
     1     0;
   219     1;
   219     2;
   219     3;];

. 。

Suppose, I want to replace elements of the 2nd column , which are less than 1, with 1. 假设我想用1替换小于1的第二列的元素。

Ie, my expected matrix would be, 也就是说，我的预期矩阵是

coords = [
     1     1;
     1     1;
   219     1;
   219     2;
   219     3;];

So, I tried to do the following, 因此，我尝试执行以下操作，

coords(:,coords(:, 2)<1) = 1;

It is not working. 它不起作用。

How to achieve that? 如何实现呢？

Answer 1

you almost got it: 您几乎明白了：

 coords(coords(:,2)<1,2)=1;

it is the first entry you want to edit at the 2nd col... 这是您要在第二行编辑的第一个条目。