CODEWITHSUNDEEP
c++
kirio
kirio

Reputation: 33

C++ Error: no matching function for call to ‘simplex615<arbitraryFunc>::amoeba

I'm trying to implement some C++ code to find the maximum of a function using a simplex algoithm. Unfortunately, I have zero experience in C++. I'm running into this error and can't seem to find a solution from answers to similar questions.

simplex.cpp: In function ‘int main(int, char**)’:
simplex.cpp:22:25: error: no matching function for call to ‘simplex615::amoeba(arbitraryFunc&, double)’
simplex.amoeba(foo, 1e-7);

There is also warning related to the linked file "simplex615.h"

In file included from simplex.cpp:4:0:
simplex615.h:302:6: note: candidate: void simplex615::amoeba(optFunc&, double) [with F = arbitraryFunc]
void simplex615 ::amoeba(optFunc& foo, double tol) {
simplex615.h:302:6: note: no known conversion for argument 1 from ‘arbitraryFunc’ to ‘optFunc&

simplex.cpp 

#include <vector>
#include <cmath>
#include <iostream>
#include "simplex615.h"
#define ZEPS 1e-10

// function object used as an argument
class arbitraryFunc {
    public:
    double operator() (std::vector<double>& x) {
        // f(x0,x1) = 100*(x1-x0^2)^2 + (1-x0)^2
        return 100*(x[1]-x[0]*x[0])*(x[1]-x[0]*x[0])+(1-x[0])*(1-x[0]);
    }
};

int main(int main, char** argv) {
    double point[2] = {-1.2, 1};
    arbitraryFunc foo;
    // initial point to start
    // WILL BE DISCUSSED LATER
    simplex615 <arbitraryFunc> simplex(point, 2); // create a simplex
    simplex.amoeba(foo, 1e-7);  // optimize for a function
    // print outputs
    std::cout << "Minimum = " << simplex.ymin() << ", at ("
    << simplex.xmin()[0] << ", " << simplex.xmin()[1]
    << ")" << std::endl;
    return 0;
}

simplex615.h

template <class F> // F is a function object
void simplex615 <F>::amoeba(optFunc& foo, double tol) {
  evaluateFunction(foo);
  while(true) {
    evaluateExtremes();
    prepareUpdate();

    if ( check_tol(Y[idxHi],Y[idxLo],tol) ) break;

    updateSimplex(foo, -1.0); // reflection

    if ( Y[idxHi] < Y[idxLo] ) {
      updateSimplex(foo, -2.0); // expansion
    }
    else if ( Y[idxHi] >= Y[idxNextHi] ) {
      if ( !updateSimplex(foo, 0.5) ) {
    contractSimplex(foo);
      }
    }
  }
}

simplex615.h 

class optFunc {
   public:
      virtual double operator() (std::vector<double>& x) = 0;
};

Link to the complete files simplex.cpp and simplex.h: Source code

Any help will be appreciated. Thanks.

Upvotes: 2

Views: 58

Answers (1)

Ashkan
Ashkan

Reputation: 1085

It seems to me that in your simplex615.h you have forgotten to use 'class F' in amoeba method. Just replace optFunc with F and it should fix the problem.

template <class F> // F is a function object
void simplex615 <F>::amoeba(F& foo, double tol) {
...
}

A template class argument in C++ defines a general type which can be replaced when using the template.

Also from this example, you can remove the declaration of optFunc from the header file.

Upvotes: 1

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