How to add elements to a sparse matrix

Dear community,

I have a sparse matrix S with the dimensions 2028 rows by 14809 columns. I would like to turn S into a full matrix F with the dimensions 2028 rows by 14927 columns. This means that I would like to define a 2028x14927 matrix of zeros first and then fill it with the elements of S in the correct place.

Here is a small example: Below you can see the first 4 elements of the sparse matrix:

         (1,1)             1
         (1,2)             2
         (1,3)             2
         (1,6)             8
        ...

I would like to turn into something like this:

         (1,1)             1
         (1,2)             2
         (1,3)             2
         (1,4)             0
         (1,5)             0
         (1,6)             8
        ...

Any ideas? Thank you! Paul

[Walter Roberson]

I have to wonder if that is the best approach?

https://www.mathworks.com/matlabcentral/answers/348521-the-most-efficient-way-to-add-a-new-column-or-new-row-to-a-sparse-matrix#answer_274100

Answer 1

[Julie]

 F=full(S)
 F=[F,zeros(2028,14927-14809)];

Answer 2

[Walter Roberson]

S(end, 14927) = 0;
S = full(S) ;

Answer 3

[Yokesh]

%Create a random 10 x 10 sparse matrix
X = sprand(10,10,0.2);

%For adding elements to an existing Sparse matrix
X(2,2) = 0.025;
X(9,1) = 0.5;

for i = [2 3 5]
    X(i,i) = 0.00375;
end

All these assignments will just add data to the existing Sparse matrix