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#ifndef __RVLALG_UMIN_CHOOSER_H
#define __RVLALG_UMIN_CHOOSER_H

#include "umintable.hh"
#include "lbfgsalg.hh"
#include "lnsrchBT.hh"
#include "uminstep.hh"
//#include "TRalg.hh" under construction

/** "Chooser" class for UMin methods - closed handle to StateAlg */

namespace RVLUmin {
  using namespace RVLAlg;
  using RVL::Vector;
  using RVL::Functional;
  using RVL::FunctionalEvaluation;

  template<class Scalar>
  class UMinMethod: public StateAlg< Vector<Scalar> > {
    
  private:

    Functional<Scalar> const & f;
    Vector<Scalar> & x;
    UMinTable<Scalar> & t;
    mutable int count;
    ostream & str;

    UMinMethod();
    UMinMethod(const UMinMethod<Scalar> &);

  public:

    UMinMethod(Functional<Scalar> const & _f,
	       Vector<Scalar> & _x,
	       UMinTable<Scalar> & _t,
	       ostream & _str = cout)
      : f(_f), x(_x), t(_t), str(_str), count(0) {}

    void run() {
      try {

	string upd;
	// check that update type is specified
	if (t.getValue("UpdateAlg",upd)) {
	  RVLException e;
	  e<<"Error: UMinMethod constructor\n";
	  e<<"update method not specified (key UpdatedAlg)\n";
	  throw e;
	}
	if (upd == "LBFGS") {
	  // BFGS update rule - also a terminator
	  LBFGSDir<Scalar> dir(f.getDomain(),
			       getValFromTable<Scalar>(t,"InvHessianScale"),
			       getValFromTable<int>(t,"MaxUpdates"),
			       str); 
	  // for LBFGS must specify line search method
	  // if (t.getValue("LineSearchAlg",lns)) {
	  //	    RVLException e;
	  //	    e<<"Error: UMinMethod constructor\n";
	  //	    e<<"line search method not specified (key LineSearchAlg) for LBFGS update\n";
	  //	    throw e;
	  //	  }
	  //if (lns == "DS") {
	  //    meth = new UMinLBFGS_DS<Scalar>(f,x,t,str);
	  //  }
	  //else
	  //	  if (lns == "BT") {

	  BacktrackingLineSearchAlg<Scalar>
	    ls(getValFromTable<int>(t,"MaxSample"),
	       getValFromTable<bool>(t,"DispFlag"),
	       str,
	       getValFromTable<Scalar>(t,"FirstStep"),
	       getValFromTable<Scalar>(t,"FcnDecreaseTol"),
	       getValFromTable<Scalar>(t,"StepReductionFactor"),
	       getValFromTable<Scalar>(t,"FractionOfMaxStep")
	       );

	  FunctionalEvaluation<Scalar> fx(f,x);

	  CountingIterationTable<Scalar> 
	    stop1(fx,
		 getValFromTable<int>(t,"MaxItn"),
		 getValFromTable<Scalar>(t,"AbsGradTol"),
		 getValFromTable<Scalar>(t,"RelGradTol"),
		 getValFromTable<bool>(t,"DispFlag"),
		 str);
	  
	  OrTerminator stop(dir,stop1);

	  UMinStepLS<Scalar> step(fx,dir,ls,str);

	  LoopAlg Umin(step, stop);

	  Umin.run();
	  
	  count=stop1.getCount();

	}
	else if (upd == "TRCG") {
	  RVLException e;
	  e<<"Error UMinMethod constructor\n";
	  e<<"TRCG currently not available\n";
	  throw e;
	  /*
	  cout << "Update = TRCG!" << endl;
	 
	  dir = new TRCGDir<Scalar>(f.getDomain(), NULL, 
				    getValFromTable<Scalar>(t,"InvHessianScale"), 
				    getValFromTable<int>(t,"MaxUpdates")); 
	 
	  meth = new UMinAlgTR<Scalar>
	    (f,x, *dir,
	     getValFromTable<int>(t,"MaxItn"),
	     getValFromTable<Scalar>(t,"GradTol"),
	     getValFromTable<bool>(t,"DispFlag"),
	     str);
	  */
	}
	else {
	  RVLException e;
	  e<<"Error: UMinMethod constructor\n";
	  e<<"UpdateAlg = "<<upd<<" has illegal value\n";
	  e<<"see docs for UMinMethod for currently available choices\n";
	  throw e;
	}	  
      }
      catch (RVLException & e) {
	e<<"\ncalled from UMinMethod constructor\n";
	throw e;
      }
    }

    ~UMinMethod() {}

    Vector<Scalar> & getState() {
      return x;
    }
    Vector<Scalar> const & getState() const {
      return x;
    }

    int getCount() const { return count; }
  };

}
#endif