gemv for sparse, rectangular matrices?

[damienhocking]

Is there a recommended routine in the MKL that can do a GEMV with the transpose of a rectangular sparse matrix?  I know I can pad it to square but I'd prefer not to have to do that.  These sparse matrices could be large, 10 million+ nonzeroes and a million rows or columns. 

Damien

[Zhen_Z_Intel]

Hi,

You provided BLAS level 2 function for sparse matrix. For sparse matrix, we normally use compressed data structure that Intel MKL supports CSR, CSC, COO, diagonal and skyline. You could learn more from developer reference about usage with different matrix structure& data compression format:

https://software.intel.com/en-us/node/520802

[damienhocking]

Yes, but the docs are all for a square m x m matrix.  I have rectangular matrices.  

[Zhen_Z_Intel · Accepted solution]

Hi,

mkl_?<format>gemv is designed for square, but mkl_?<format>mv can be used for rectangular matrix (m * k). Or, you could use Inspector-execute sparse function mkl_sparse_?_mv, normally would provide a better performance. 

[damienhocking]

Thank you Fiona, that's exactly what I wanted.