rama_krish627
rama_krish627
Branch Unspecified
18 Nov 2008

Sparse Matrix

Hi
Can any one tell me how to represent a Sparse Matrix using arrays.
and also how to add two sparse matrices.😲
manupep

manupep

Branch Unspecified
18 Nov 2008
sparse matrix is a matrix contain large no of elements but most of them are zeros("0") . So inorder to save the memory utilization we are not storing the zeros, only othr elements. Any sparse matrix has only 3 colums . but the row number depends on the number of non-zero elements.

format is

<row-no> <column-no> <value>
<row-no> <column-no> <value>
-------------------------------
eg:

3 0
0 8 reprents in sparse form as

0 0 3
1 1 8

I cant explain the whole procedure of adding becz i'min office now

first you make sure that order of 3 matx are same. then sameposition elements should be added and make the resultant. I think u can able to make the logic.
komputergeek

komputergeek

Branch Unspecified
19 Nov 2008
//Addition

k=n2;
for(i=0;i<n1;i++)
{
      flag=0;
      for(j=0;j<n2;j++)
      {
            if( a[i][0] == b[j][0] && a[i][1]==b[j][1] )
            {
                    flag=1;
                    break;
             }
      }
      if( flag==1)
             b[j][2]=b[j][2] + a[i][2];
      else
       {
             b[k][0]=a[i][0];
             b[k][1]=a[i][1];
             b[k][2]=a[i][2];
             b[k][0]=b[i][0];
             b[k][1]=b[i][1];
             b[k][2]=b[i][2];
             k++;
        }
}

//result of addition is stored in b
This is just a logic.I haven't compiled the code.So expect errors in it 😎
Let me know if it works.
niraj.kumar

niraj.kumar

Branch Unspecified
20 Nov 2008
just want to add ... the purpose of sparse matrix is 2 save memory and it is used when you have few information is a big space. So to preserve the memory we use sparse matrix
rama_krish627

rama_krish627

Branch Unspecified
21 Nov 2008
ok fine I understood what it is.

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