"Sparse Matrix Paired". What is it like?

Question

Programming

In general, I came across a problem, there was this concept, maybe someone came across this and knows what it is?
An internet search turned up nothing of the sort.

Answer 1

I didn’t come across it myself, but a simple search on the wiki gave an article . It also contains a sentence that gives the key to understanding: "One of the possible storage options is by rows. Each row contains a list of non-zero elements and a list of their indices.". Let's say we have a matrix like this:

1, 0, 0, 5, 0 -1
7, 2, 0, 1, 1, 0
0, 0, 0, 5, 6, 1

it can be rewritten as a matrix consisting of pairs (vectors):

(0,1),(3,5),(5,-1)
(0,7),(1,2),(3,1),(4,1)
(3,5),(4,6),(5,1)

where the first number is the column number in the row (counting from zero), and the second is the number itself.