quadratic.hpp

// BSD 3-Clause License
//
// Copyright (C) 2019-2025, LAAS-CNRS, University of Edinburgh,
// Heriot-Watt University
// Copyright note valid unless otherwise stated in individual files.
// All rights reserved.

#ifndef CROCODDYL_CORE_ACTIVATIONS_QUADRATIC_HPP_
#define CROCODDYL_CORE_ACTIVATIONS_QUADRATIC_HPP_

#include "crocoddyl/core/activation-base.hpp"
#include "crocoddyl/core/fwd.hpp"

namespace crocoddyl {

template <typename _Scalar>
class ActivationModelQuadTpl : public ActivationModelAbstractTpl<_Scalar> {
 public:
 EIGEN_MAKE_ALIGNED_OPERATOR_NEW
 CROCODDYL_DERIVED_CAST(ActivationModelBase, ActivationModelQuadTpl)

 typedef _Scalar Scalar;
 typedef MathBaseTpl<Scalar> MathBase;
 typedef ActivationModelAbstractTpl<Scalar> Base;
 typedef ActivationDataAbstractTpl<Scalar> ActivationDataAbstract;
 typedef typename MathBase::VectorXs VectorXs;
 typedef typename MathBase::MatrixXs MatrixXs;

 explicit ActivationModelQuadTpl(const std::size_t nr) : Base(nr) {};
 virtual ~ActivationModelQuadTpl() = default;

 virtual void calc(const std::shared_ptr<ActivationDataAbstract>& data,
 const Eigen::Ref<const VectorXs>& r) override {
 if (static_cast<std::size_t>(r.size()) != nr_) {
 throw_pretty(
 "Invalid argument: " << "r has wrong dimension (it should be " +
 std::to_string(nr_) + ")");
 }
 data->a_value = Scalar(0.5) * r.dot(r);
 };

 virtual void calcDiff(const std::shared_ptr<ActivationDataAbstract>& data,
 const Eigen::Ref<const VectorXs>& r) override {
 if (static_cast<std::size_t>(r.size()) != nr_) {
 throw_pretty(
 "Invalid argument: " << "r has wrong dimension (it should be " +
 std::to_string(nr_) + ")");
 }

 data->Ar = r;
 // The Hessian has constant values which were set in createData.
 assert_pretty(MatrixXs(data->Arr).isApprox(MatrixXs::Identity(nr_, nr_)),
 "Arr has wrong value");
 };

 virtual std::shared_ptr<ActivationDataAbstract> createData() override {
 std::shared_ptr<ActivationDataAbstract> data =
 std::allocate_shared<ActivationDataAbstract>(
 Eigen::aligned_allocator<ActivationDataAbstract>(), this);
 data->Arr.diagonal().setOnes();
 return data;
 };

 template <typename NewScalar>
 ActivationModelQuadTpl<NewScalar> cast() const {
 typedef ActivationModelQuadTpl<NewScalar> ReturnType;
 ReturnType res(nr_);
 return res;
 }

 virtual void print(std::ostream& os) const override {
 os << "ActivationModelQuad {nr=" << nr_ << "}";
 }

 protected:
 using Base::nr_;
};

} // namespace crocoddyl

CROCODDYL_DECLARE_EXTERN_TEMPLATE_CLASS(crocoddyl::ActivationModelQuadTpl)

#endif // CROCODDYL_CORE_ACTIVATIONS_QUADRATIC_HPP_