MATLAB: Sorting columns with empty cells

Question

Dear all,'

I have the following column and as you can see the 1rst, 40th, 79th asnd so forth are mising

     ''
    '23-11-2008'
    '21-12-2008'
    '18-01-2009'
    '15-02-2009'
    '15-03-2009'
    '12-04-2009'
    '10-05-2009'
    '07-06-2009'
    '05-07-2009'
    '02-08-2009'
    '30-08-2009'
    '27-09-2009'
    '25-10-2009'
    '22-11-2009'
    '20-12-2009'
    '24-01-2010'
    '21-02-2010'
    '21-03-2010'
    '18-04-2010'
    '16-05-2010'
    '13-06-2010'
    '11-07-2010'
    '08-08-2010'
    '05-09-2010'
    '03-10-2010'
    '31-10-2010'
    '28-11-2010'
    '26-12-2010'
    '23-01-2011'
    '20-02-2011'
    '20-03-2011'
    '17-04-2011'
    '15-05-2011'
    '12-06-2011'
    '12-07-2011'
    '07-08-2011'
    '04-09-2011'
    '02-10-2011'
    ''
    '23-11-2008'
    '21-12-2008'
    '18-01-2009'
    '15-02-2009'
    '15-03-2009'
    '12-04-2009'
    '10-05-2009'
    '07-06-2009'
    '05-07-2009'
    '02-08-2009'
    '30-08-2009'
    '27-09-2009'
    '25-10-2009'
    '22-11-2009'
    '20-12-2009'
    '24-01-2010'
    '21-02-2010'
    '21-03-2010'
    '18-04-2010'
    '16-05-2010'
    '13-06-2010'
    '11-07-2010'
    '08-08-2010'
    '05-09-2010'
    '03-10-2010'
    '31-10-2010'
    '28-11-2010'
    '26-12-2010'
    '23-01-2011'
    '20-02-2011'
    '20-03-2011'
    '17-04-2011'
    '15-05-2011'
    '12-06-2011'
    '12-07-2011'
    '07-08-2011'
    '04-09-2011'
    '02-10-2011'
    ''
    '23-11-2008'

I want to sort out a bigger matrix say mdata1 using the code

 d=datenum(mdata1(:,11),'dd-mm-yyyy');
[l,idx]=sortrows(d);
zoi=mdata1(idx,:);
where mdata1(:,11), is the above column
the problem is that some cells are empty as i said  before
and the matlab stucks at command datenu

Is there anything I can to avoid this problem withou creating a fake date for the empty cells?

thanks in advance

Answer 1

d1 = mdata1(:,11);
d1(cellfun('isempty',d1)) = {'00-00-0000'};
[id,id] = sort(datenum(d1,'dd-mm-yyyy'));
out = mdata1(id,11);