rama_krish627
Branch Unspecified
21 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

Branch Unspecified
10 years ago
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

Branch Unspecified
10 years ago
```//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

Branch Unspecified
10 years ago
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

Branch Unspecified
10 years ago
ok fine I understood what it is.