Anders Logg wrote:
> On Wed, Apr 09, 2008 at 06:32:48PM +0100, Garth N. Wells wrote:
>>
>> Anders Logg wrote:
>>> On Wed, Apr 09, 2008 at 06:14:35PM +0200, Ola Skavhaug wrote:
>>>> Dag Lindbo skrev den 09/04-2008 følgende:
>>>>> Hello again!
>>>>>
>>>>> Why is it not possible any longer to get the Vector associated with a
>>>>> Function? E.g:
>>>>>
>>>>> #include <dolfin.h>
>>>>> using namespace dolfin;
>>>>>
>>>>> int main()
>>>>> {
>>>>> Function u;
>>>>> Vector& v = u.vector();
>>>>> }
>>>> int main()
>>>> {
>>>> Function u;
>>>> Vector v;
>>>> v = u.vector();
>>>> return 0;
>>>> }
>>>>
>>>> Should work. A Function returns a GenericVector reference, and the Vector
>>>> reference needs to be a Vector. Then the operator= in Vector is applied in
>>>> the
>>>> assignment.
>>>>
>>>> Ola
>>> I don't think one should need to make a copy of the vector. It should
>>> work to either use the vector you get by calling vector() directly,
>>> for example
>>>
>>> solve(A, u.vector(), b); // Doesn't work currently but it should!
>>>
>>> You may also do
>>>
>>> GenericVector& x = u.vector();
>>>
>> This works. Can someone remind me how to convert a GenericVector into
>> the underlying vector type( e.g. a uBlasVector or a PETScVector)?
>>
>> Garth
>
> If x is a GenericVector, then
>
> PETScVector* xx = dynamic_cast<PETScVector*>(&x);
> if (xx == 0)
> error("Not a PETSc Vector.");
>
Could we add a member function to GenericVector/GenericMatrix to do this?
template < class T>
T* foo(GenericVector& x)
{
T* xx = dynamic_cast<T*>(&x);
if (xx == 0)
error("Not a ??? Vector.");
return xx;
}
Garth
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