dolfin team mailing list archive

[Murtazo Nazarov <murtazo@xxxxxxxxxx>]

Garth Wells wrote:
> Question #97399 on DOLFIN changed:
> https://answers.launchpad.net/dolfin/+question/97399
>
>     Status: Open => Answered
>
> Garth Wells proposed the following answer:
>
> Murtazo Nazarov wrote:
>   
> > New question #97399 on DOLFIN:
> > https://answers.launchpad.net/dolfin/+question/97399
> >
> >
> > In example in /demo/ode/stiff/cpp/Timedependent1.h I tried to change function f(u,t) into
> >
> >
> >   void f(const real* u, real t, real* y)
> >   {
> >     y[0] = -1000.0 * u[0] + cos(t);
> >   }
> >
> > But I get a compilation error:
> >
> > In file included from main.cpp:12:
> > TestProblem1.h: In member function 'virtual void TestProblem1::f(const dolfin::real*, dolfin::real, dolfin::real*)':
> > TestProblem1.h:27: error: cannot convert 'dolfin::real' to 'double' for argument '1' to 'double cos(double)'
> > scons: *** [main.o] Error 1
> >
> > It seems dolfin::real is not double by default for the latest dolfin. Is it bug or I can fix it easily in my code?
> > Any suggestion? 
> >
> >     
>
> Use 'double'.
>
> Garth
>   

I tried with 'double'.

 void u0(double* u)
 {
   u[0] = 1.0;
 }

 void f(const double* u, double t, double* y)
 {
   y[0] = -1000.0 * u[0] + cos(t);
 }

Then I got similar error

main.cpp:64: error: cannot declare variable 'test_problem' to be of 
abstract type 'TestProblem1'
TestProblem1.h:12: note:   because the following virtual functions are 
pure within 'TestProblem1':
/afs/nada.kth.se/home/x/u18gh7kx/data/Work/fenics/build/include/dolfin/ode/ODE.h:83: 
note:     virtual void dolfin::ODE::u0(dolfin::real*)

The I tried like this:

 void u0(real* u)
 {
   u[0] = 1.0;
 }

 void f(const real* u, double t, double* y)
 {
   y[0] = -1000.0 * u[0] + cos(t);
 }

Still error:

In file included from main.cpp:12:
TestProblem1.h: In member function 'void TestProblem1::f(const 
dolfin::real*, double, double*)':
TestProblem1.h:27: error: cannot convert '__gmp_expr<__mpf_struct [1], 
__gmp_binary_expr<__gmp_expr<__mpf_struct [1], __gmp_binary_expr<double, 
__gmp_expr<__mpf_struct [1], __mpf_struct [1]>, __gmp_binary_multiplies> 
>, double, __gmp_binary_plus> >' to 'double' in assignment
scons: *** [main.o] Error 1


>   
> > Thanks,
> > Murtazo
> >
> >
> >     
>
>