dolfin team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

On Tue, Oct 30, 2007 at 07:52:00PM +0100, Alessio Quaglino wrote:
> > On Wed, Oct 24, 2007 at 04:58:56PM +0200, Alessio Quaglino wrote:
> >> > On Sat, Oct 20, 2007 at 01:12:14PM +0200, Alessio Quaglino wrote:
> >> >> > On Fri, Oct 12, 2007 at 12:53:50PM +0200, Alessio Quaglino wrote:
> >> >> >> I've compiled dolfin using PETSc. After some work, everything
> >> finally
> >> >> >> compiles, but there was no way to make those working inside
> >> >> PETScVector:
> >> >> >>
> >> >> >> /// Return value of maximum component of vector
> >> >> >> real max() const;
> >> >> >>
> >> >> >> /// Return value of minimum component of vector
> >> >> >> real min() const;
> >> >> >
> >> >> > What do you mean? Do you need to remove those two in order to
> >> compile?
> >> >>
> >> >> Thank you for the reply.
> >> >> Yes, I needed to remove them in order to compile.
> >> >>
> >> >>
> >> >> >> I thought you wanted to know it, just in case you want to dump
> >> them
> >> >> (max
> >> >> >> is just the linf norm so it's not even necessary).
> >> >> >
> >> >> > Yes, I think they can be removed. Any objections?
> >> >> >
> >> >> > (Or we should add them to the GenericMatrix interface.)
> >> >> >
> >> >> >> I have also another question: why is uBlas necessary for
> >> compiling?
> >> >> >> Wouldn'it be (at least in theory) possible to use just PETSc?
> >> >> >
> >> >> > It would break the ODE solvers since they assume the uBlas
> >> interface.
> >> >> > Since uBlas is fairly standard, part of boost, just a collection of
> >> >> > header files and is part of Debian, it's generally not a problem to
> >> >> > rely on uBlas.
> >> >>
> >> >> Ok thanks I was just thinking how to speedup the "code generation"
> >> phase
> >> >> (after compiling and linking) in Visual Studio which takes about 5
> >> >> minutes. Compiling is quite fast because I'm using dolfin as a static
> >> >> library, but then the code generation is bloody slow (the full dolfin
> >> >> .lib
> >> >> was about 120 mb which became 90mb after some "cutting", but it seems
> >> >> that
> >> >> the rest is sort of linked together). I've been told that boost could
> >> be
> >> >> a
> >> >> cause, so I just considered to experiment.
> >> >>
> >> >> Alessio
> >> >
> >> > Sounds very strange. What "code generation phase" do you mean?
> >> > Compiling your program, or generating code with FFC?
> >> >
> >> > I'm not sure what your compiler does, but I'm looking a libdolfin.so
> >> > which weights in at 15 MB. Stripped from comments etc (command strip),
> >> > it's down to 3.2 MB
> >>
> >> Usually when I compile the solver with Visual Studio there are three
> >> phases: compiling, linking and generation of code (I think Visual Studio
> >> means the generation of the executable). The first two are pretty fast
> >> (faster than in linux), but the third one is extremely slow, probably
> >> because the static library libdolfin.lib I generate putting all the
> >> dolfin
> >> source files in a project and compiling is about 120 MB.
> >>
> >> Alessio
> >
> > Sounds like a lot of fun... How about using gcc?
> 
> I wish I could but (unfortunately) I must use the Windows compiler which,
> however, is much faster in pure compiling and produces slightly more
> optimized code.
> 
> By the way, I've seen that you modified the PETScMatrix mat() function but
> it looks like still "const". As I said, though it compiles with the
> "const" definition, wouldn't it be better to leave the user the
> possibility to use all the functions that PETSc has available and not only
> those implemented in dolfin?
> 
> Alessio

There is no such limitation. The user is free to use any function
available in PETSc. For example, try the following:

  PETScMatrix A(2, 2);
  
  int rows[2] = {0, 1};
  int cols[2] = {0, 1};
  double block[4] = {1.0, 2.0, 3.0, 4.0};

  MatSetValues(A.mat(), 2, rows, 2, cols, block, INSERT_VALUES);
  MatAssemblyBegin(A.mat(), MAT_FINAL_ASSEMBLY);
  MatAssemblyEnd(A.mat(), MAT_FINAL_ASSEMBLY);

  A.disp();

You should get the following output:

  row 0: (0, 1)  (1, 2) 
  row 1: (0, 3)  (1, 4) 

/Anders