[petsc-users] Large rectangular Dense Transpose multiplication with sparse

[Ghosh, Swarnava]

Dear all,

  I am trying to compute matrices A = transpose(R)*H*R and M = transpose(R)*R 
where 
  H is a sparse (banded) matrix in MATMPIAIJ format (5 million x 5 million 
total size) 
  R is a MPI dense matrix of size 5 million x 2000.

  I tried 1) MatPtAP - Failed, realized this only works for pairs of AIJ 
matrices  
          2) First multiplying H*R and storing in 5 million x 2000 MPI dense. 
Then MatTranspose of R and multiplying the transposed R with 5 million x 2000 
dense. This multiplication fails. 
          
   Could someone please suggest a way of doing this.
  
Regards,
Swarnava 
-- 
Swarnava Ghosh