////////////////////////////////////////////////////////////////
//  $Id: TMinuitMinimizer.cxx,v 1.5 2007/10/31 04:56:55 ltrung Exp $
//
// Implement the base class for function minimizers.

#include <iostream>
#include <exception>
#include <limits>


#include "TMinuitMinimizer.hxx"

COMET::TMinuitMinimizer::TMinuitMinimizer(COMET::IMinimizerFunc& func) 
    : COMET::IMinimizer(func),
      TMinuit(func.GetParameterCount()) { }



Int_t COMET::TMinuitMinimizer::Eval(Int_t npar, Double_t *grad,
                       Double_t &fval, Double_t *par, Int_t flag)
{
    fval = fFunction.Evaluate(par);
      
    return 0;
}


double COMET::TMinuitMinimizer::GetParameter(int ipar) const {
    double value = 0.0;
    double error = 0.0;
    TMinuit::GetParameter(ipar, value, error);
    
    return value;
    
}



double COMET::TMinuitMinimizer::GetCovariance(int i, int j) const {
    int npars = fFunction.GetParameterCount();
    double cov[npars*npars];
    const_cast<COMET::TMinuitMinimizer*>(this)->mnemat(cov,npars);
    return cov[i*npars+j];
}

double COMET::TMinuitMinimizer::GetMinimum(void) const {
    return fMinimum;
};

int COMET::TMinuitMinimizer::GetStatus(void) const {
    return fStatus;
};

void COMET::TMinuitMinimizer::SetPrecision(double accuracy) {
    double arglist[1];
    arglist[0] = accuracy;
    Int_t ierr = 0;
    mnexcm("SET ERR",arglist,1,ierr);
};

Int_t COMET::TMinuitMinimizer::SetPrintLevel(int printLevel) {
    TMinuit::SetPrintLevel(printLevel);
    return 0;
};

int COMET::TMinuitMinimizer::Minimize(int nPar, double *par) {
    double arglist[4];
    
    if (nPar > fFunction.GetParameterCount()) throw EParameterCount();
    
        // Assign initial values for the parameters.
    Int_t ierr = 0;
    for (int i = 0; i < nPar; ++i) {
        mnparm(i,fFunction.GetParameterName(i),
               par[i],                // Value
               fFunction.GetScale(i), // Scale
               0,0,ierr);             // Bounds
    }
    
        // Call the MIDGRAD algorithm to get the minimum
    mnexcm("MIGRAD",arglist,0,ierr);

    fStatus = ierr;
    
        // Get the values for the parameters.
    for (int i=0; i<nPar; ++i) par[i] = GetParameter(i);

        // Calculate the value of the function
    fMinimum = fFunction.Evaluate(par);


    return fStatus;
}