export dense matrix to CSR format, how to optimized?

nvh10 — Fri, 16 Sep 2022 08:35:52 GMT

Hello everyone,

I have a dense matrix A. I know the structure of A is sparse and I don't know the number or the location of non-zero elements in A.

I want to cover A to the sparse matrix by CSR format. The array of pointerB, pointerE, column index, and nonzero value is the target output.

Here is my program:

program Console24 implicit none double precision A(5,5) INTEGER nnz_A,i,j,t,k integer, allocatable, dimension (:)::c_A INTEGER ia(6),pB_A(5),pE_A(5) double precision, allocatable, dimension (:)::v_A A=0d0 A(3,4)=1.2d0 A(3,1)=1.2d0 A(3,3)=1.3d0 A(5,1)=1.7d0 A(2,4)=0.2d0 A(2,1)=4.2d0 A(2,3)=5.3d0 A(2,1)=3.7d0 nnz_A=count(A/=0) allocate (c_A(nnz_A),v_A(nnz_A)) k=1 t=1 ia(1)=1 do j=1,5 do i=1,5 if (A(j,i)/=0) then v_A(t)=A(j,i) c_A(t)=i t=t+1 endif enddo ia(j+1)=ia(j)+count(A(j,:)/=0) enddo pB_A=ia(1:5) pE_A=ia(2:6) end program Console24

The code runs well but it takes so long time for the large size of A, for example A(100000,100000). Is there any function in mkl library similar to my program or is there any way to speed up the calculation?

Please help me!

Re: export dense matrix to CSR format, how to optimized?

Gajanan_Choudhary — Tue, 20 Sep 2022 18:01:26 GMT

Hi @nvh10 ,

Thanks for reaching out to us about this. Have you tried using mkl_?dnscsr function for this purpose? Note that that function is deprecated, so I would not advise its long-term use as it may be removed from oneMKL in the future. However, it is unlikely the removal would happen without first providing an alternative function in its place, so it may be temporarily safe for use for now.

Regards,

Gajanan

(Developer in oneMKL team)

topic export dense matrix to CSR format, how to optimized? in Intel® oneAPI Math Kernel Library

export dense matrix to CSR format, how to optimized?

Re: export dense matrix to CSR format, how to optimized?