On Tue, Jul 14, 2015 at 8:03 PM, Jared Crean <[email protected]> wrote:
> Hello, > PETSC_USE_COMPLEX isn't a symbol in the shared library when Petsc > is built with complex scalars, so I don't see a way to access it at > runtime. I'll have to write a simple C program that uses sizeof() and write > the value to a file. > That is crazy. How about isComplex = PETSC_COMPLEX == PETSC_SCALAR Matt > As for the MPI communicator, the julia MPI package uses a C int to > store it, so I will typealias to that to ensure consistency. If an MPI > implementation uses an 8 byte pointer, MPI.jl will have to change too. > > Jared Crean > > > On 7/14/2015 1:04 PM, Matthew Knepley wrote: > > On Tue, Jul 14, 2015 at 10:56 AM, Jared Crean <[email protected]> wrote: > >> Hello everyone, >> I got the package in a reasonably working state and Travis >> testing setup, so I am putting the package up on Github. >> >> https://github.com/JaredCrean2/PETSc.jl >> >> There is still a lot more work to do, but its a start. >> >> A couple questions: >> When looking though the code, I noticed the MPI communicator is >> being passed as a 64 bit integer. mpi.h typedefs it as an int, so >> shouldn't it be a 32 bit integer? >> > > Some MPI implementations store the communicator as a pointer, which may > be 64 bits. I think the only thing the standard says is > that MPI_Comm should be defined. > > >> Also, is there a way to find out at runtime what datatype a >> PetscScalar is? It appears PetscDataTypeGetSize does not accept >> PetscScalar as an argument. >> > > If PETSC_USE_COMPLEX is defined its PETSC_COMPLEX, otherwise its > PETSC_REAL. You can also just use sizeof(PetscScalar). What do you > want to do? > > Thanks, > > Matt > > >> >> Jared Crean >> >> >> >> On 07/06/2015 09:02 AM, Matthew Knepley wrote: >> >> On Mon, Jul 6, 2015 at 4:59 AM, Patrick Sanan <[email protected]> >> wrote: >> >>> I had a couple of brief discussions about this at Juliacon as well. I >>> think it would be useful, but there are a couple of things to think about >>> from the start of any new attempt to do this: >>> 1. As Jack pointed out, one issue is that the PETSc library must be >>> compiled for a particular precision. This raises some questions - should >>> several versions of the library be built to allow for flexibility? >>> 2. An issue with wrapping PETSc is always that the flexibility of using >>> the PETSc options paradigm is reduced - how can this be addressed? >>> Could/should an expert user be able to access the options database >>> directly, or would this be too much violence to the wrapper abstraction? >>> >> >> I have never understood why this is an issue. Can't you just wrap our >> interface level, and use the options just as we do? That >> is essentially what petsc4py does. What is limiting in this methodology? >> On the other hand, requiring specific types, ala FEniCS, >> is very limiting. >> >> Matt >> >> >>> On Sat, Jul 4, 2015 at 11:00 PM, Jared Crean <[email protected]> >>> wrote: >>> >>>> Hello, >>>> I am a graduate student working on a CFD code written in Julia, >>>> and I am interested in using Petsc as a linear solver (and possibly for the >>>> non-linear solves as well) for the code. I discovered the Julia wrapper >>>> file Petsc.jl in Petsc and have updated it to work with the current version >>>> of Julia and the MPI.jl package, using only MPI for communication (I don't >>>> think Julia's internal parallelism will scale well enough, at least not in >>>> the near future). >>>> >>>> I read the discussion on Github [ >>>> https://github.com/JuliaLang/julia/issues/2645], and it looks like >>>> there currently is not a complete package to access Petsc from Julia. >>>> With your permission, I would like to use the Petsc.jl file as the basis >>>> for developing a package. My plan is create a lower level interface that >>>> exactly wraps Petsc functions, and then construct a higher level interface, >>>> probably an object that is a subtype of Julia's AbstractArray, that allows >>>> users to store values into Petsc vectors and matrices. I am less >>>> interested in integrating tightly with Julia's existing linear algebra >>>> capabilities than ensuring good scalability. The purpose of the high level >>>> interface it simple to populate the vector or matrix. >>>> >>>> What do you think, both about using the Petsc.jl file and the >>>> overall approach? >>>> >>>> Jared Crean >>>> >>> >>> >> >> >> -- >> What most experimenters take for granted before they begin their >> experiments is infinitely more interesting than any results to which their >> experiments lead. >> -- Norbert Wiener >> >> >> > > > -- > What most experimenters take for granted before they begin their > experiments is infinitely more interesting than any results to which their > experiments lead. > -- Norbert Wiener > > > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener
