coeff_optimiser.h

Go to the documentation of this file.

/* Copyright (c) 2008-2022 the MRtrix3 contributors.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * Covered Software is provided under this License on an "as is"
 * basis, without warranty of any kind, either expressed, implied, or
 * statutory, including, without limitation, warranties that the
 * Covered Software is free of defects, merchantable, fit for a
 * particular purpose or non-infringing.
 * See the Mozilla Public License v. 2.0 for more details.
 *
 * For more details, see http://www.mrtrix.org/.
 */
 
#ifndef __dwi_tractography_sift2_coeff_optimiser_h__
#define __dwi_tractography_sift2_coeff_optimiser_h__
 
 
#include "math/golden_section_search.h"
#include "math/quadratic_line_search.h"
#include "misc/bitset.h"
 
#include "dwi/tractography/SIFT/track_index_range.h"
#include "dwi/tractography/SIFT/types.h"
 
#include "dwi/tractography/SIFT2/streamline_stats.h"
 
 
//#define SIFT2_COEFF_OPTIMISER_DEBUG
 
 
namespace MR {
  namespace DWI {
    namespace Tractography {
      namespace SIFT2 {
 
 
 
      class TckFactor;
 
 
 
      class CoefficientOptimiserBase
      { MEMALIGN(CoefficientOptimiserBase)
        public:
          CoefficientOptimiserBase (TckFactor&, StreamlineStats&, StreamlineStats&, unsigned int&, BitSet&, double&);
          CoefficientOptimiserBase (const CoefficientOptimiserBase&);
          virtual ~CoefficientOptimiserBase();
 
          bool operator() (const SIFT::TrackIndexRange&);
 
 
        protected:
          TckFactor& master;
          const double mu;
 
          virtual double get_coeff_change (const SIFT::track_t) const = 0;
 
 
#ifdef SIFT2_COEFF_OPTIMISER_DEBUG
          size_t total, failed, wrong_dir, step_truncated, coeff_truncated;
#endif
 
 
        private:
          StreamlineStats& step_stats;
          StreamlineStats& coefficient_stats;
          unsigned int& nonzero_streamlines;
          BitSet& fixels_to_exclude;
          double& sum_costs;
 
          StreamlineStats local_stats_steps, local_stats_coefficients;
          size_t local_nonzero_count;
          BitSet local_to_exclude;
 
        protected:
          mutable double local_sum_costs;
 
        private:
          double do_fixel_exclusion (const SIFT::track_t);
 
      };
 
 
 
 
 
 
 
 
      // Golden Section Search within the permitted range
      class CoefficientOptimiserGSS : public CoefficientOptimiserBase
      { MEMALIGN(CoefficientOptimiserGSS)
 
        public:
          CoefficientOptimiserGSS (TckFactor&, StreamlineStats&, StreamlineStats&, unsigned int&, BitSet&, double&);
          CoefficientOptimiserGSS (const CoefficientOptimiserGSS&);
          ~CoefficientOptimiserGSS() { }
 
        private:
          double get_coeff_change (const SIFT::track_t) const;
 
      };
 
 
 
 
 
      // Performs a Quadratic Line Search within the permitted domain
      // Does not requre derivatives; only needs 3 seed points (two extremities and 0.0)
      // Note however if that these extremities are large, the initial CF evaluation may be NAN!
      class CoefficientOptimiserQLS : public CoefficientOptimiserBase
      { MEMALIGN(CoefficientOptimiserQLS)
 
        public:
          CoefficientOptimiserQLS (TckFactor&, StreamlineStats&, StreamlineStats&, unsigned int&, BitSet&, double&);
          CoefficientOptimiserQLS (const CoefficientOptimiserQLS&);
          ~CoefficientOptimiserQLS() { }
 
        private:
          Math::QuadraticLineSearch<double> qls;
 
          double get_coeff_change (const SIFT::track_t) const;
 
      };
 
 
 
 
      // Coefficient optimiser based on iterative root-finding Newton / Halley
      // Early exit if outside the permitted coefficient step range and moving further away
      class CoefficientOptimiserIterative : public CoefficientOptimiserBase
      { MEMALIGN(CoefficientOptimiserIterative)
 
        public:
          CoefficientOptimiserIterative (TckFactor&, StreamlineStats&, StreamlineStats&, unsigned int&, BitSet&, double&);
          CoefficientOptimiserIterative (const CoefficientOptimiserIterative&);
          ~CoefficientOptimiserIterative();
 
        private:
          double get_coeff_change (const SIFT::track_t) const;
 
#ifdef SIFT2_COEFF_OPTIMISER_DEBUG
          mutable uint64_t iter_count;
#endif
 
      };
 
 
 
 
 
      }
    }
  }
}
 
 
#endif