ROL_GenMoreauYosidaCVaR.hpp

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#ifndef ROL_GENMOREAUYOSIDACVAR_HPP
#define ROL_GENMOREAUYOSIDACVAR_HPP

#include "ROL_ExpectationQuad.hpp"

namespace ROL {

template<class Real>
class GenMoreauYosidaCVaR : public ExpectationQuad<Real> {
private:

  Real prob_;
  Real lam_;
  Real eps_;

  Real alpha_;
  Real beta_;

  Real omp_;
  Real oma_;
  Real bmo_;
  Real lb_;
  Real ub_;

  void checkInputs(void) const {
    Real zero(0), one(1);
    TEUCHOS_TEST_FOR_EXCEPTION((prob_ <= zero) || (prob_ >= one), std::invalid_argument,
      ">>> ERROR (ROL::GenMoreauYosidaCVaR): Confidence level must be between 0 and 1!");
    TEUCHOS_TEST_FOR_EXCEPTION((lam_ < zero) || (lam_ > one), std::invalid_argument,
      ">>> ERROR (ROL::GenMoreauYosidaCVaR): Convex combination parameter must be positive!");
    TEUCHOS_TEST_FOR_EXCEPTION((eps_ <= zero), std::invalid_argument,
      ">>> ERROR (ROL::GenMoreauYosidaCVaR): Smoothing parameter must be positive!");
  }

  void setParameters(void) {
    const Real one(1);
    omp_   = one-prob_;
    alpha_ = lam_;
    beta_  = (one-alpha_*prob_)/omp_;
    oma_   = one-alpha_;
    bmo_   = beta_-one;
    lb_    = -eps_*oma_;
    ub_    =  eps_*bmo_;
  }

public:
  GenMoreauYosidaCVaR(Real prob, Real eps )
    : ExpectationQuad<Real>(), prob_(prob), lam_(0), eps_(eps) {
    checkInputs();
    setParameters();
  }

  GenMoreauYosidaCVaR(Real prob, Real lam, Real eps )
    : ExpectationQuad<Real>(), prob_(prob), lam_(lam), eps_(eps) {
    checkInputs();
    setParameters();
  }

  GenMoreauYosidaCVaR(Teuchos::ParameterList &parlist)
    : ExpectationQuad<Real>() {
    Teuchos::ParameterList& list
      = parlist.sublist("SOL").sublist("Risk Measure").sublist("Generalized Moreau-Yosida CVaR");
    prob_ = list.get<Real>("Confidence Level");
    lam_  = list.get<Real>("Convex Combination Parameter");
    eps_  = list.get<Real>("Smoothing Parameter");
    checkInputs();
    setParameters();
  }

  Real error(Real x, int deriv = 0) {
    Real zero(0), one(1);
    Real X = ((deriv==0) ? x : ((deriv==1) ? one : zero));
    return regret(x,deriv) - X;
  }

  Real regret(Real x, int deriv = 0) {
    Real zero(0), half(0.5), one(1), reg(0);
    if ( x <= lb_ ) {
      reg = ((deriv == 0) ? alpha_*x + half*lb_*oma_
          : ((deriv == 1) ? alpha_ : zero));
    }
    else if ( x >= ub_ ) {
      reg = ((deriv == 0) ? beta_*x - half*ub_*bmo_
          : ((deriv == 1) ? beta_ : zero));
    }
    else {
      reg = ((deriv == 0) ? half/eps_*x*x + x
          : ((deriv == 1) ? x/eps_ + one : one/eps_));
    }
    return reg;
  }

  void checkRegret(void) {
    ExpectationQuad<Real>::checkRegret();
    Real zero(0), one(1), two(2), p1(0.1);
    // Check v'(ub)
    Real x = ub_;
    Real vx = zero, vy = zero;
    Real dv = regret(x,1);
    Real t = one;
    Real diff = zero;
    Real err = zero;
    std::cout << std::right << std::setw(20) << "CHECK REGRET: v'(ub) is correct? \n";
    std::cout << std::right << std::setw(20) << "t"
                            << std::setw(20) << "v'(x)"
                            << std::setw(20) << "(v(x+t)-v(x-t))/2t"
                            << std::setw(20) << "Error"
                            << "\n";
    for (int i = 0; i < 13; i++) {
      vy = regret(x+t,0);
      vx = regret(x-t,0);
      diff = (vy-vx)/(two*t);
      err = std::abs(diff-dv);
      std::cout << std::scientific << std::setprecision(11) << std::right
                << std::setw(20) << t
                << std::setw(20) << dv
                << std::setw(20) << diff
                << std::setw(20) << err
                << "\n";
      t *= p1;
    }
    std::cout << "\n";
    // check v''(ub) 
    vx = zero;
    vy = zero;
    dv = regret(x,2);
    t = one;
    diff = zero;
    err = zero;
    std::cout << std::right << std::setw(20) << "CHECK REGRET: v''(ub) is correct? \n";
    std::cout << std::right << std::setw(20) << "t"
                            << std::setw(20) << "v''(x)"
                            << std::setw(20) << "(v'(x+t)-v'(x-t))/2t"
                            << std::setw(20) << "Error"
                            << "\n";
    for (int i = 0; i < 13; i++) {
      vy = regret(x+t,1);
      vx = regret(x-t,1);
      diff = (vy-vx)/(two*t);
      err = std::abs(diff-dv);
      std::cout << std::scientific << std::setprecision(11) << std::right
                << std::setw(20) << t
                << std::setw(20) << dv
                << std::setw(20) << diff
                << std::setw(20) << err
                << "\n";
      t *= p1;
    }
    std::cout << "\n"; 
    // Check v'(0)
    x = zero;
    vx = zero;
    vy = zero;
    dv = regret(x,1);
    t = one;
    diff = zero;
    err = zero;
    std::cout << std::right << std::setw(20) << "CHECK REGRET: v'(0) is correct? \n";
    std::cout << std::right << std::setw(20) << "t"
                            << std::setw(20) << "v'(x)"
                            << std::setw(20) << "(v(x+t)-v(x-t))/2t"
                            << std::setw(20) << "Error"
                            << "\n";
    for (int i = 0; i < 13; i++) {
      vy = regret(x+t,0);
      vx = regret(x-t,0);
      diff = (vy-vx)/(two*t);
      err = std::abs(diff-dv);
      std::cout << std::scientific << std::setprecision(11) << std::right
                << std::setw(20) << t
                << std::setw(20) << dv
                << std::setw(20) << diff
                << std::setw(20) << err
                << "\n";
      t *= p1;
    }
    std::cout << "\n";
    // check v''(0) 
    vx = zero;
    vy = zero;
    dv = regret(x,2);
    t = one;
    diff = zero;
    err = zero;
    std::cout << std::right << std::setw(20) << "CHECK REGRET: v''(0) is correct? \n";
    std::cout << std::right << std::setw(20) << "t"
                            << std::setw(20) << "v''(x)"
                            << std::setw(20) << "(v'(x+t)-v'(x-t))/2t"
                            << std::setw(20) << "Error"
                            << "\n";
    for (int i = 0; i < 13; i++) {
      vy = regret(x+t,1);
      vx = regret(x-t,1);
      diff = (vy-vx)/(two*t);
      err = std::abs(diff-dv);
      std::cout << std::scientific << std::setprecision(11) << std::right
                << std::setw(20) << t
                << std::setw(20) << dv
                << std::setw(20) << diff
                << std::setw(20) << err
                << "\n";
      t *= p1;
    }
    std::cout << "\n"; 
    // Check v'(lb)
    x = lb_;
    vx = zero;
    vy = zero;
    dv = regret(x,1);
    t = one;
    diff = zero;
    err = zero;
    std::cout << std::right << std::setw(20) << "CHECK REGRET: v'(lb) is correct? \n";
    std::cout << std::right << std::setw(20) << "t"
                            << std::setw(20) << "v'(x)"
                            << std::setw(20) << "(v(x+t)-v(x-t))/2t"
                            << std::setw(20) << "Error"
                            << "\n";
    for (int i = 0; i < 13; i++) {
      vy = regret(x+t,0);
      vx = regret(x-t,0);
      diff = (vy-vx)/(two*t);
      err = std::abs(diff-dv);
      std::cout << std::scientific << std::setprecision(11) << std::right
                << std::setw(20) << t
                << std::setw(20) << dv
                << std::setw(20) << diff
                << std::setw(20) << err
                << "\n";
      t *= p1;
    }
    std::cout << "\n";
    // check v''(lb) 
    vx = zero;
    vy = zero;
    dv = regret(x,2);
    t = one;
    diff = zero;
    err = zero;
    std::cout << std::right << std::setw(20) << "CHECK REGRET: v''(lb) is correct? \n";
    std::cout << std::right << std::setw(20) << "t"
                            << std::setw(20) << "v''(x)"
                            << std::setw(20) << "(v'(x+t)-v'(x-t))/2t"
                            << std::setw(20) << "Error"
                            << "\n";
    for (int i = 0; i < 13; i++) {
      vy = regret(x+t,1);
      vx = regret(x-t,1);
      diff = (vy-vx)/(two*t);
      err = std::abs(diff-dv);
      std::cout << std::scientific << std::setprecision(11) << std::right
                << std::setw(20) << t
                << std::setw(20) << dv
                << std::setw(20) << diff
                << std::setw(20) << err
                << "\n";
      t *= p1;
    }
    std::cout << "\n"; 
  }

};

}
#endif