How can I sort a two-dimensional array in MATLAB with respect to a single column?

Question

I would like to sort the matrix according to a specific column. There is a sort function, but it sorts all columns independently.

For example, if my matrix is data :

  1 3 5 7 -1 4 

Then the desired result (sorting by the first column) will be:

 -1 4 1 3 5 7 

But the output of sort(data) :

 -1 3 1 4 5 7 

How can I sort this matrix by first column?

Answer 1

I think the sortrows function is what you are looking for.

 >> sortrows(data,1) ans = -1 4 1 3 5 7 

Answer 2

An alternative to sortrows() , which can be applied to wider scripts.

• save the sort indexes of the row / column you want to order:

   [~,idx]=sort(data(:,1)); 

• reorder all rows / columns according to previous sorted indexes

   data=data(idx,:)