smooth-2norm.hpp

// BSD 3-Clause License
//
// Copyright (C) 2020, LAAS-CNRS
// Copyright note valid unless otherwise stated in individual files.
// All rights reserved.
 
#ifndef CROCODDYL_CORE_ACTIVATIONS_SMOOTH_2NORM_HPP_
#define CROCODDYL_CORE_ACTIVATIONS_SMOOTH_2NORM_HPP_
 
#include <stdexcept>
 
#include "crocoddyl/core/activation-base.hpp"
#include "crocoddyl/core/fwd.hpp"
#include "crocoddyl/core/utils/exception.hpp"
 
namespace crocoddyl {
 
template <typename _Scalar>
class ActivationModelSmooth2NormTpl
    : public ActivationModelAbstractTpl<_Scalar> {
 public:
  EIGEN_MAKE_ALIGNED_OPERATOR_NEW
 
  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 ActivationModelSmooth2NormTpl(const std::size_t nr,
                                         const Scalar eps = Scalar(1.))
      : Base(nr), eps_(eps) {
    if (eps < Scalar(0.)) {
      throw_pretty("Invalid argument: "
                   << "eps should be a positive value");
    }
  };
  virtual ~ActivationModelSmooth2NormTpl() {};
 
  virtual void calc(const boost::shared_ptr<ActivationDataAbstract>& data,
                    const Eigen::Ref<const VectorXs>& r) {
    if (static_cast<std::size_t>(r.size()) != nr_) {
      throw_pretty("Invalid argument: "
                   << "r has wrong dimension (it should be " +
                          std::to_string(nr_) + ")");
    }
    using std::sqrt;
    data->a_value = sqrt(r.squaredNorm() + eps_);
  };
 
  virtual void calcDiff(const boost::shared_ptr<ActivationDataAbstract>& data,
                        const Eigen::Ref<const VectorXs>& r) {
    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 / data->a_value;
    using std::pow;
    data->Arr.diagonal().array() = Scalar(1) / pow(data->a_value, 3);
  };
 
  virtual boost::shared_ptr<ActivationDataAbstract> createData() {
    return boost::allocate_shared<ActivationDataAbstract>(
        Eigen::aligned_allocator<ActivationDataAbstract>(), this);
  };
 
 protected:
  virtual void print(std::ostream& os) const {
    os << "ActivationModelSmooth2Norm {nr=" << nr_ << ", eps=" << eps_ << "}";
  }
 
  using Base::nr_;  
  Scalar eps_;      
};
 
}  // namespace crocoddyl
 
#endif  // CROCODDYL_CORE_ACTIVATIONS_SMOOTH_2NORM_HPP_