Thanks for the reponse. I am just starting to use PETsC so it might be a little while. But eventually i think it might be useful to have (for myself and maybe other people might find it useful as well).
The reason i need it, is that i have old codes that store the matrices in this format and i just wanted to "plug in" PETsC solvers. The old codes use solvers that we wrote ourselves. Anyway, thanks for the pointers. I have to see how i'll proceed. thanks mat On Friday 30 June 2006 19:04, Barry Smith wrote: > Mat, > > There is no routine like this. It would be possible for you or > someone else to provide a routine that worked for a particular matrix > format such as MatCreateSeqAIJFromCoordinates(comm,nz,i,j,values,&mat) > It likely would be essentially like the code you have written except it > would put the values directly into the data structure without having to use > calls to MatSetValues()[You would need to look at MatSetValues_SeqAIJ() to > see one way of getting the data directly in]. > > Similar code could be written for MPIAIJ though it gets more > complicated because of the more complicated structure and if you place > values off-processor. It could also be written for only PETSc matrix > formats, BAIJ, SBAIJ, Bdiag etc. > > We haven't written this codes because we haven't needed them and much > prefer to simply put the matrix values into the matrix WHEN they are > generated rather then store them in some data-structure that has to be then > converted into the PETSc format. > > If you would like to provide a routine like this we'd be glad to add it > to PETSc and maintain it. > > Barry > > On Fri, 30 Jun 2006, Matt Funk wrote: > > Hi, > > > > i have a matrix stored in the matrix free format. I.e. an array > > indicating the row number, an array storing the column number and the > > array of corresponding values. > > > > I was wondering what the best way is to build the PETsC matrix using > > this. I was hoping that there is call to some sparse matrix assembler > > function to which is simply pass these three arrays and it builds the > > matrix for me. > > > > However, i did not find anything that simple. So i guess i need to do it > > row by row using the MatSetValues fcn() after allocating the memory for > > the matrix (i.e. pretty much as the procedure described on p.54 of the > > user manual)? > > > > mat > > > > On Friday 30 June 2006 14:30, Satish Balay wrote: > >> Added to petsc-dev now. > >> > >> Satish > >> > >> On Fri, 30 Jun 2006, Barry Smith wrote: > >>> Mathieu, > >>> > >>> Cool, thanks. > >>> > >>> Satish, > >>> > >>> Could you please apply the diff to petsc-dev now and then push > >>> so any future changes anyone makes will be combatiable with the new > >>> code. > >>> > >>> Thanks > >>> > >>> Barry > >>> > >>> On Fri, 30 Jun 2006, Mathieu Taillefumier wrote: > >>>> Good morning everybody, > >>>> > >>>> I finished to modify the code of the library in order to compile the > >>>> complex version with a C compiler. A few numbers of files have been > >>>> modified. This modifications include a modification of the file > >>>> language.py where I put in comment two lines forcing to compile the > >>>> library with a c++ compiler. Since I don't really know python, I just > >>>> put them as a comment, but i think it is better to put a message > >>>> indicating that compiling the complex version of Petsc needs a C90 > >>>> compliant compiler (gcc 3.4 and after work, it works also with icc) > >>>> and is experimental. Actually I am working with this modifications and > >>>> it seems to work like a charm (I had no problem with it). > >>>> I still need some time to convert the example programs which do not > >>>> compile but it will be done soon. > >>>> Note for all of us : > >>>> Don't use the name I as a variable anymore. It is a reserved word > >>>> of the language. > >>>> For most of us, the modifications must be transparent. > >>>> > >>>> Regards > >>>> > >>>> Mathieu
