Could you help me to get started with this complex task?

Here on the pic there is 10 columns, and a lot more rows. The columns represent firing of cells, the rows represent time points. Essentially I need all the time points (rows) when a cell (column) is fired. (represented with a '1' as opposed to '0', I guess this is what we call a logical array). So essentially my task would be to extract all the '1'-s, from all the columns, so from column 1 to column 10. i've been told that I need a for-loop for this, but I dont know how to start this. Could someone help me out? Thanks a lot!

Answer 1

[Geoff Hayes]

Abel - your cells variable is a 1440000x10 double array, so loop over each row as

 numRows = size(cells,1);

 for k=1:numRows
     % do something
 end

The do something in the above block would be the line or lines of code that would check to see which columns have a one. For example you could do something like

 numRows = size(cells,1);

 for k=1:numRows
     rowData = cells(k,:);

     if any(rowData)

         % then at least one column within this row contains a one
         % and so has fired
         fprintf('row %d has at least one column that has fired',k);
     end
 end

The above code will iterate over each row of cells (you may want to consider renaming this variable) and print a list of all row numbers that have at least one column with a one in it.

The any function determines if any array elements are non-zero (returns true if at least one element is non-zero).