Sequence of a specific number in a matrix

Hey

So my trouble is that I have a matrix, here a an example becuase my original matrix is really big.

   0   1   1   1   0
   0   1   0   1   1
   1   1   0   0   0
   1   1   1   0   1
   0   1   1   1   1

Now I want the sequences of 1 in each row so I get something like:

   3
   1 2
   2
   3 1
   4
   

It is possible?

Answer 1

[Star Strider]

Try this:

M = [  0   1   1   1   0
       0   1   0   1   1
       1   1   0   0   0
       1   1   1   0   1
       0   1   1   1   1];

dM = diff([zeros(size(M(:,1))), M, zeros(size(M(:,1)))], 1, 2);
for k1 = 1:size(M,1)
    first = strfind(dM(k1,:), 1);
    last = strfind(dM(k1,:), -1);
    dif{k1,:} = last - first;
end
cols = max(cellfun(@(x)size(x,2), dif));
Result = zeros(size(M,1),cols);
for k1 = 1:size(M,1)
    Result(k1,1:numel(dif{k1})) = dif{k1};
end

producing

Result =
     3     0
     1     2
     2     0
     3     1
     4     0

The actual output is in the ‘dif’ cell array. The code after that and the second loop simply converts it to a double array I call ‘Result’.