Eigen sparse matrix

1. What is dense vs sparse matrix?
2. How do you represent a sparse matrix?
3. How to make a sparse matrix in Java?

What is dense vs sparse matrix?

Matrices that contain mostly zero values are called sparse, distinct from matrices where most of the values are non-zero, called dense.

How do you represent a sparse matrix?

Linked List representation of the sparse matrix. In a linked list representation, the linked list data structure is used to represent the sparse matrix. The advantage of using a linked list to represent the sparse matrix is that the complexity of inserting or deleting a node in a linked list is lesser than the array.

How to make a sparse matrix in Java?

For the matrix to be sparse, count of zero elements present in an array must be greater than size/2. Number of zeroes present in above matrix is 6 and size of the matrix is 3 * 3 = 9. Since, 6 > 4.5 that means, most elements of given array are zero. Hence, the above matrix is a sparse matrix.