On Thu, Dec 10, 2009 at 10:33:42AM -0800, Johan Hake wrote: > On Thursday 10 December 2009 10:17:46 Garth N. Wells wrote: > > Johan Hake wrote: > > > On Wednesday 09 December 2009 01:08:38 Garth N. Wells wrote: > > >> [email protected] wrote: > > >>> ------------------------------------------------------------ > > >>> revno: 4340 > > >>> committer: Johan Hake <[email protected]> > > >>> branch nick: dolfin > > >>> timestamp: Tue 2009-12-08 23:42:50 -0800 > > >>> message: > > >>> Work on SWIG interface of Array and Expression > > >>> - Need to sort out what we want: > > >>> > > >>> Array<const double>& or const Array<double>& > > >>> > > >>> The latter is to prefer when constructing typemaps > > >> > > >> The latter looks nicer, but since Array wraps a pointer, I don't know > > >> how to create an Array<double> from a const double* pointer without > > >> using const_cast. > > > > > > Yes, I used that in the old eval calling the new eval. Would this be an > > > issue once we have removed the old eval? I did not try it, but I just > > > assume it would be difficult to make a const double * out of a double * > > > but now I see that this is the easy one ;) If we want the prior one, I > > > can try to change it back. > > > > I'm about to commit code where I've changed it back in the C++ > > interface. I don't see at the moment how to avoid Array<const double> > > since we often use Array to wrap a const pointer. For example, Data has > > member data > > > > Array<const double> x; > > > > and we update frequently the array to which x points. > > Fine, I did not have time to do it yesterday. If you have not done it, I can > update the SWIG interface code. > > Should we change all double* and uint* to Array? There are still some left in > the low level la interface. This would make it possible to erase all > numpy_typemaps.
I think so, or at least in all functions that we wrap to Python.
> I am also not sure the boost::shared_array works for all circumstances of
> memory management. Not sure this case is relevant, but say we have a method
> that returns an Array. Instead of returning the Array we want to return a
> NumPy array. Then we have to let the NumPy array take control of the data.
I don't think it happens that often. The C++ interface never (?)
returns data from function other than simple scalars.
If we have
void compute_foo(Array& x);
in C++, then it should be wrapped to
x = compute_foo()
in Python and then some glue code will be needed anyway and that code
would first create NumPy array, wrap that into an Array and send it to
compute_foo.
--
Anders
> Is this possible with the boost::shared_array? I was thinking of using a
> private is_view attribute instead?
>
> The nice thing with shared_array is that we can control the ownership through
> two nice and simple constructors.
>
> Johan
>
> > Garth
> >
> > >>> - Compiled expression call now kind off works:
> > >>>
> > >>> e = Expression('sin(x[0])')
> > >>> e(pi/2,0) == 1
> > >>>
> > >>> - Array.array() returns a NumPy view of the data.
> > >>>
> > >>> - Need to clean up the SWIG code...
> > >>
> > >> Should we add a file 'Array.i'? Then it's clear where all the Array
> > >> magic happens.
> > >
> > > Not sure it will work out properly. We need to put the class
> > > specializations in common_{pre,post}.i, and then we need the typemaps a
> > > head of everything, as we handle most of the other typemaps today. This
> > > is a minor detail as common is the first module to be included in
> > > interface, but it is at least consistent with the other SWIG interface
> > > files.
> > >
> > > I put the Array typemap in function_pre.i temporarily, as it otherwise
> > > would interfere with the copy-constructor of Array. We can easily avoid
> > > this by calling the argument 'other' instead of 'x' in the copy
> > > constructor.
> > >
> > > Johan
> >
>
> _______________________________________________
> Mailing list: https://launchpad.net/~dolfin
> Post to : [email protected]
> Unsubscribe : https://launchpad.net/~dolfin
> More help : https://help.launchpad.net/ListHelp
signature.asc
Description: Digital signature
_______________________________________________ Mailing list: https://launchpad.net/~dolfin Post to : [email protected] Unsubscribe : https://launchpad.net/~dolfin More help : https://help.launchpad.net/ListHelp
