ROL
ROL_Gradient_U.hpp
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1// @HEADER
2// *****************************************************************************
3// Rapid Optimization Library (ROL) Package
4//
5// Copyright 2014 NTESS and the ROL contributors.
6// SPDX-License-Identifier: BSD-3-Clause
7// *****************************************************************************
8// @HEADER
9
10#ifndef ROL_GRADIENT_U_H
11#define ROL_GRADIENT_U_H
12
14#include "ROL_Types.hpp"
15#include "ROL_Step.hpp"
16
22
23namespace ROL {
24
25template<typename Real>
26class Gradient_U : public DescentDirection_U<Real> {
27public:
29
30 void compute( Vector<Real> &s, Real &snorm, Real &sdotg, int &iter, int &flag,
31 const Vector<Real> &x, const Vector<Real> &g, Objective<Real> &obj) override {
32 s.set(g.dual());
33 s.scale(static_cast<Real>(-1));
34 snorm = s.norm();
35 //sdotg = s.dot(g.dual());
36 sdotg = s.apply(g);
37 iter = 0;
38 flag = 0;
39 }
40
41 std::string printName(void) const override {
42 std::string name = "Gradient Descent";
43 return name;
44 }
45}; // class ROL::Gradient_U
46
47} // namespace ROL
48#endif
Contains definitions of custom data types in ROL.
Provides the interface to compute unconstrained optimization steps for line search.
void compute(Vector< Real > &s, Real &snorm, Real &sdotg, int &iter, int &flag, const Vector< Real > &x, const Vector< Real > &g, Objective< Real > &obj) override
std::string printName(void) const override
Provides the interface to evaluate objective functions.
Defines the linear algebra or vector space interface.
virtual Real apply(const Vector< Real > &x) const
Apply to a dual vector. This is equivalent to the call .
virtual Real norm() const =0
Returns where .
virtual void set(const Vector &x)
Set where .
virtual void scale(const Real alpha)=0
Compute where .
virtual const Vector & dual() const
Return dual representation of , for example, the result of applying a Riesz map, or change of basis,...