Question

I created a cell array in Octave. Some columns contain floats, and some columns contain strings. I am able to sort the cell array by a column of strings (say col #4), using this command:

sortrows (mycellarray, 4);

But if the column I want to sort by is a column of floats, then I get this error message:

error: sort: only cell arrays of character strings may be sorted

Does anyone know how to sort a cell array, by a column of floats?

Answer 1

Convert the column with float values to a vector, sort it and get the sorting index. Then you can apply this index to your cell array.

mycellarray = {'a',1,0.5; 'b',2,0.1; 'c',3,4.5; 'd',4,-3.2};
vector2sort=cell2mat(mycellarray(:,3));
[~,idx] = sort(vector2sort)
mycellarraysorted = mycellarray(idx,:);

In some versions of Octave, however, the tilde ~ operator is not defined. In that case:

vector2sort = mycellarray(:,3); 
[dummy,idx] = sort(vector2sort); 
mycellarraysorted = mycellarray(idx,:);