I'm dealing with SVDLIBC library. In order to compute singular values I need to specify my matrix in the Harwell-Boeing format. On Internet I have found next example:
Dense Text Format:
4 3
2.3 0 4.2
0 1.3 2.2
3.8 0 0.5
0 0 0
Sparse Text Harwell-Boeing Format:
SVDLIBC v. 1.32
3 1 1 1 0
rra
4 3 6 0
(8i) (8i) (8e) (8e)
1 3 4 7
1 3 2 1 2 3
2.3 3.8 1.3 4.2 2.2 0.5
In other libraries for sparse matrices I specified matrix as an array of non-zero values and their indices, but I can't understand how do they specify matrix in Harwell-Boeing format. Can anybody explain me how do they form two array of indices in an example above? I'm a newcomer in this field, so I'm sorry if the question seems too obvious.