Hands-On High Performance with Go

CSR matrix

CSR matrices use three one-dimensional arrays to represent a matrix. The CSR format uses these three arrays:

• A: Values present within the array.
• IA: The index in which each of these values is present. These are defined as follows:
  • The value of IA at the 0 index, IA[0] = 0
  • The value of IA at the i index, IA[i] = IA[i − 1] + (number of non-zero elements on the i-1^th row in the original matrix)
• JA: Stores the column indices of the elements.

The following image shows an example of a 4 x 4 matrix. This is the matrix that we are going to use in our following code sample:

We can calculate these values as follows:

• A = [ 1 2 3 4]