Thanks Bruno for your prompt reply,
I got the important part of the code compiling, however since I am new to
this lambda (functional) functions, I do not know how to pass the new
definitions to SolverBFGS.
Looking at your suggestion I do the following:
class Shape_compute {
public:
Parameters par;
Shape_compute (Parameters epar):par(epar) {
Register([=]( Vector<double> ex, Vector<double> dx ){ return
objective_fun (ex,dx); });
}
void Register(std::function<double(Vector<double>, Vector<double>)>
Callback) {} //fun = objective_fun;
double objective_fun ( Vector<double> ex, Vector<double> dx) {
vector<double> x (par.design_N), grad (par.design_N);
for (unsigned int i=0; i < x.size (); i++) {
x [i] = ex(i);
}
Adaptive::DtN_Helmholtz<2> fem (par, x, true);
fem.run ();
double objective_function = fem.objective_function;
for (unsigned int i=0; i < par.design_N; i++) {
if (i < par.design_N) {
vector<double> aux = x; aux [i] += h;
Adaptive::DtN_Helmholtz<2> fem (par, aux, false);
fem.run ();
grad [i] = (fem.objective_function - objective_function
)/h;
}
dx(i) = grad [i];
}
iteration++;
return objective_function;
}
};
Then, when calling the optimization routine:
Vector<double> X (N);
SolverControl residual_control (N, 1e-7);
//SolverBFGS::AdditionalData data (10, true);
SolverBFGS<Vector<double> > opt (residual_control);//, data);
Shape_compute polar(par);
opt.solve ( polar.Callback, X ); // If this line is commented, it
compiles fine!
I would appreciate guidance on how to achieve this,
Thanks in advance,
Juan Carlos Araújo
On Friday, 25 October 2019 17:55:03 UTC+2, Bruno Turcksin wrote:
>
> Juan,
>
> Take a look at
> https://stackoverflow.com/questions/17131768/how-to-directly-bind-a-member-function-to-an-stdfunction-in-visual-studio-11
>
> I advise using a lambda like the second reply suggests
>
> Best,
>
> Bruno
>
> On Friday, October 25, 2019 at 10:53:08 AM UTC-4, Juan Carlos Araujo
> Cabarcas wrote:
>>
>> Dear all,
>>
>> I would like to use SolverBFGS from deal.II/optimization/ in my project,
>> and I try to follow the documentation in
>> https://www.dealii.org/current/doxygen/deal.II/classSolverBFGS.html
>>
>> First, I would like to mention that the documentation would really
>> improve by adding a minimal example on how to use SolverBFGS.
>>
>> In my project, I cannot just define an independent function to be pass to
>> SolverBFGS.
>> Instead, I define a class ShapePolar, which needs to be initialized with
>> some mesh parameters par, as in
>>
>> ShapePolar polar (par);
>>
>> then I have implemented the function
>>
>> double ShapePolar::fun (const Vector<double>, Vector<double>)
>>
>> that computes a scalar value of an objective function and its gradient
>> Vector, when we pass X.
>>
>>
>> Then, my attempt, after looking at the documentation, is to do something
>> like this:
>>
>> Vector<double> X (N);
>>
>> SolverControl residual_control (N, 1e-7);
>> //SolverBFGS::AdditionalData data (10, true);
>>
>> SolverBFGS<Vector<double> > opt (residual_control); //, data);
>>
>> ShapePolar polar (par);
>> std::function<double(const Vector<double>, Vector<double>)> fun =
>> polar.fun;
>>
>> opt.solve ( fun, X );
>>
>> After several failed attempts (syntax errors), I realize that I am
>> missing something fundamental here and could use some guidance.
>> I would appreciate any hint on how to achieve using SolverBFGS for the
>> setting described above.
>>
>> Kind regards,
>> Juan C. Araújo Cabarcas
>>
>>
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