James: > > > Thanks a lot for looking into this. I'm still working on debugging this on > our side. It might be an issue with us. I will keep you updated. >
Take your time. Hong > > ----- Original Message ----- > From: "Hong" <[email protected]> > To: "Barry Smith" <[email protected]> > Cc: "James A Charles" <[email protected]>, "Hong" <[email protected]>, > [email protected], "PETSc users list" <[email protected]>, "Daniel > Mejia" <[email protected]>, "Tillmann Kubis" <[email protected]> > Sent: Sunday, April 5, 2015 6:13:42 PM > Subject: Re: [petsc-users] MatMatMult with dense matrices. > > > James, > > > My understanding is that > you call MatMatMult in sequential for computing C = A*B, in which > A is in aij format, and B is dense, and the product C is dense, but gives > different values than what you got from Matlab. > > > Do you have a stand-alone petsc code to reproduce this so I can > investigate what goes wrong? > > > Hong > > > > On Sun, Apr 5, 2015 at 3:44 PM, Barry Smith < [email protected] > wrote: > > > > We would need to see the PETSc side of the code to see if there is > anything wrong there. > > > > > On Apr 5, 2015, at 3:35 PM, James A Charles < [email protected] > > wrote: > > > > Hi Hong, > > > > You can open up matmatmult_comparison.mat in MATLAB ( load > matmatmult_comparison.mat ). That .mat contains A, B, C, and C_MATLAB. I > called matmatmult in sequential. We use AIJ when A2 was sparse but at the > time of this multiplication everything was dense. > > > > Thanks, > > James > > > > > > ----- Original Message ----- > > From: "Hong" < [email protected] > > > To: "James A Charles" < [email protected] > > > Cc: "PETSc users list" < [email protected] >, [email protected] , > "Daniel Mejia" < [email protected] >, "Tillmann Kubis" < [email protected] > > > > Sent: Sunday, April 5, 2015 4:25:39 PM > > Subject: Re: [petsc-users] MatMatMult with dense matrices. > > > > > > > > > > James: > > > > > > I'm multiplying two dense matrices. I compared the results against > MATLAB and I am getting different results. Attached you will see a zip that > contains a .mat file that has the A, B, and C. C_MATLAB is the > multiplication of A*B in MATLAB and C is the PETSc 3.4.3 result. I also > attached the .m files A, B, and C that were saved from PETSc. Is there > something I'm doing wrong or > > > > > > What is the file type of matmatmult_comparison.mat? > > How to read it? > > I need to see how it defers from C.m. > > > > > > > > any reason due to the shape of the matrices that this would fail? If it > gives any more information we convert the previous matrix that A is formed > of A2 (A = A1*A2) to dense prior to the multiplication using MatConvert. > > > > > > > > It seems both A and B are dense, complex square matrices. > > Did you call MatMatMult() in sequential or parallel? What matrix format > did you use? > > > > > > Hong > > >
