Find specific column of matrix in symmetric CSR format

[kim__seongik]

Hello,

I'm finding about the subroutine which can find specific column values of matrix in symmetric CSR format..
Is there any subroutine for this purpose??

If not, how can I get the certain column or row values of matrix in symmetric CSR format?

Thank you for reading

[mecej4 · Accepted solution]

You do not have instant access to any given column; in fact a particular column may not exist, since only non-zero values are stored in a sparse matrix represented.

You can search within a row for a particular column, since the row is ordered in increasing column indices. Linear search is simpler to program, but binary search can be used for speed when the matrices are large.

If you find yourself doing such searches by column indices often, you have to reassess your choice of the CSR representation as being appropriate.

[Khang_N_Intel]

Hi Seongik,

Mecej4 is correct.

There is no MKL function to do that.

Best,

Khang