Adding rows with constraint

a=[10,11,8; 6,5,7; 4,6,5; 0,0,5]; output=[10,11,8; 16,16,15; 20,22,20; 0,0,25];

First row should be as it is, in the second row elements should be added, in the third row also elements should be added but in the final row if '0' is there that column should not be added column with out '0' has to be added.

Answer 1

[dpb]

b=cumsum(a); 
b(a==0)=0;

[Bathrinath]

Thank you sir its working

Answer 2

[David Sanchez]

 a=[

      10,11,8; 
      6,5,7; 
      4,6,5; 
      0,0,5]; 
  output = zeros(size(a));
  output(1,:) = a(1,:);% First row should be as it is
  output(2,:) = sum(a(1:2,:),1); % the second row elements should be added
  output(3,:) = sum(a(1:3,:),1);
  output(4,:) = sum(a(1:4,:),1).*(a(4,:)~=0);%  final row if '0' is there that column should not be added column with out '0' has to be added.
  >> output

output =

      10    11     8
      16    16    15
      20    22    20
       0     0    25