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
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.
Provides the interface to compute optimization steps with the gradient descent method globalized usin...
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,...