Please help me in inserting ones in a given matrix in special rows

Suppose if I already have a matrix 'X' having only one '1' in few rows and other rows contains zeros only for example matrix given below

X =

    [0     0     0     0     1     0     0     0     0     0;
     0     1     0     0     0     0     0     0     0     0;
     0     0     1     0     0     0     0     0     0     0;
     0     0     0     0     0     0     0     0     0     0;
     0     0     0     0     0     0     0     0     0     0]

i need a matrix having few (specified number) '1's after existing '1' in each row.

for example output matrix is

Y =

    [0     0     0     0     1     1     1     1     0     0;
     0     1     1     1     1     1     0     0     0     0;
     0     0     1     1     1     0     0     0     0     0;
     0     0     0     0     0     0     0     0     0     0;
     0     0     0     0     0     0     0     0     0     0]

number of ones to be inserted in specified rows are D = [4; 5; 3; 2; 4];

as in example matrix last two rows are zeros only, there is no need to insert ones in those rows,as there is no '1' appearing in those rows

[José-Luis]

Where would you insert the ones if a row is only zeros?

[Stephen23]

Continuation of this question:

http://www.mathworks.com/matlabcentral/answers/293140-please-help-me-in-generating-a-matrix-of-ones-for-a-given-matrix

Answer 1

[Stephen23]

MATLAB is a high-level language, so there is no need to waste time with ugly loops as if this was some poor low-level language like C++. Vectorized code is much neater:

>> tmp = cumsum(cumsum(X,2),2);
>> Y = bsxfun(@le,tmp,D) & tmp
Y =
     0     0     0     0     1     1     1     1     0     0
     0     1     1     1     1     1     0     0     0     0
     0     0     1     1     1     0     0     0     0     0
     0     0     0     0     0     0     0     0     0     0
     0     0     0     0     0     0     0     0     0     0

Answer 2

[José-Luis]

X =  [0     0     0     0     1     0     0     0     0     0;
     0     1     0     0     0     0     0     0     0     0;
     0     0     1     0     0     0     0     0     0     0;
     0     0     0     0     0     0     0     0     0     0;
     0     0     0     0     0     0     0     0     0     0]

D = [4; 5; 3; 2; 4];
for row = 1:numel(D)
  ic = find(X(row,:));
  if ~isempty(ic)
      X(row,ic:ic+D-1)= 1;
  end          
end