How can I sort a 2-D array in MATLAB with respect to one column?

Question

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

For example, if my matrix data is:

 1     3  5     7 -1     4 

Then the desired output (sorting by the first column) would be:

-1     4  1     3  5     7 

But the output of sort(data) is:

-1     3  1     4  5     7 

How can I sort this matrix by the first column?

Answer 1

I think the sortrows function is what you're looking for.

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

Answer 2

An alternative to sortrows(), which can be applied to broader scenarios.

1. save the sorting indices of the row/column you want to order by:

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

2. reorder all the rows/columns according to the previous sorted indices

   data=data(idx,:)