CODEWITHSUNDEEP
arraysmatlabsortingmatrixindexing
Shew
Shew

Reputation: 1596

Sort a matrix according to ordering in another matrix

I am trying to sort an array based on another array. I tried the sort method with index return, but it is somehow behaving strangely.

y = [1 2 3; 2 3 4] 
x = [1 3 4; 2 2 3] 
[yy, ii] = sort(y,'descend');


yy =
   2     3     4   
   1     2     3

ii =
   2     2     2
   1     1     1

But my x(ii) is not the matrix sorted based on y.

x(ii) =  
      2     2     2
      1     1     1

I am expecting the matrix to be:

x(ii) =

    2     2     3 
    1     3     4

How can I sort the matrix x according to another matrix y?

Upvotes: 2

Views: 133

Answers (1)

Sardar Usama
Sardar Usama

Reputation: 19689

ii are row subscripts but are being inputted by you as linear indices. You need to convert them to relevant linear indices before proceeding i.e.

>> szx =  size(x);
>> x(sub2ind(szx, ii, repmat(1:szx(2),szx(1),1)))

ans =

     2     2     3
     1     3     4

Upvotes: 8

Related Questions