There might be an easier way to do this, but it works.
% get the indices of all non-empty cells
[row,col] = find(cellfun(@(x) ~isempty(x),YourCell));
% grab the cell array size
[numrows, numcols] = size(YourCell);
% preallocate
firstcol_index = NaN(numrows,1);
lastcol_index = NaN(numrows,1);
% get the first and last index for each row, leave NaN if all cols empty
for ii = 1:numrows
single_row_col_inds = col(row == ii);
if ~isempty(single_row_col_inds)
firstcol_index(ii) = min(single_row_col_inds);
lastcol_index(ii) = max(single_row_col_inds);
else
continue
end
end
