title: Replace elements in a matrix according to the coordinates in matlab
body: <p>I am curious about what is the best way to do this:
  assume I have a 10x10 zero matrix and I want to replace the zeros with ones with the known coordinates, in the beginning I am thing about write a for loop to replace the elements one by one by reading out the x and y. Is there any other easier way to do it?</p>
  
  <p>Example:</p>
  
  <pre><code>mat=zeros(10);
  x=[1,3,5,7,9]'; 
  y=[2,4,6,8,10]';
  newmat= [0 0 0 0 0 0 0 0 0 0
           1 0 0 0 0 0 0 0 0 0 
           0 0 0 0 0 0 0 0 0 0
           0 0 1 0 0 0 0 0 0 0
           0 0 0 0 0 0 0 0 0 0
           0 0 0 0 1 0 0 0 0 0
           0 0 0 0 0 0 0 0 0 0 
           0 0 0 0 0 0 1 0 0 0
           0 0 0 0 0 0 0 0 0 0
           0 0 0 0 0 0 0 0 1 0]  
  </code></pre>