reshaping a set of data

Hello, Say I have a list a experimental measures of sea surface current like:

 date       latitude      longitude    velocity
 31/11/2011   42.333      127.111     2.1
 31/11/2011   43.333      123.111     2.3
 01/1/2012    42.333      127.111     2.1
 01/1/2012   43.333      123.111     2.3
...

Note that I don't have all latitude and longitude data for all dates ( there are some experiments missing).

 I would like to reshape this to a 3d array with
 1d: date
 1d: latitude
 1d: longitude
and in the array: the velocity value.

I have looked into reshape and dataset.unstack.. without success... thanks !

Answer 1

[Andrei Bobrov]

d = {'31/11/2011'   42.333      127.111     2.1
'31/11/2011'   43.333      123.111     2.3
'01/1/2012'    42.333      127.111     2.1
'01/1/2012'   43.333      123.111     2.3};

k = [datenum(d(:,1),'dd/mm/yyyy'),cell2mat(d(:,2:end))];
[a,n,n] = arrayfun(@(ii)unique(k(:,ii)),1:size(k,2)-1,'un',0);
p = [n{:}];
out = accumarray(p(:,[2 3 1]),k(:,4));

[bb]

Thanks very much Andrei !