KernelParameters.h

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/**
 *  \file IMP/em/KernelParameters.h
 *  \brief Calculates and stores Gaussian kernel parameters.
 *
 *  Copyright 2007-2015 IMP Inventors. All rights reserved.
 *
 */

#ifndef IMPEM_KERNEL_PARAMETERS_H
#define IMPEM_KERNEL_PARAMETERS_H
#include "def.h"
#include <IMP/base_types.h>
#include <boost/scoped_array.hpp>
#include <IMP/base/exception.h>
#include <IMP/base/log.h>
#include <map>
#include <cmath>
#include <algorithm>
#include <iostream>
#include <iomanip>
#include <vector>
#include <limits>

IMPEM_BEGIN_NAMESPACE

//! Calculates kernel parameters as a function of a specific radius.
class IMPEMEXPORT RadiusDependentKernelParameters {
 public:
  RadiusDependentKernelParameters(float radii, float rsigsq, float timessig,
                                  float sq2pi3, float inv_rsigsq,
                                  float rnormfac, float rkdist);
  //! Show
  void show(std::ostream& s = std::cout) const;
  //! Gets the value of the volume sigma
  inline float get_vsig() const { return vsig_; }
  //! Gets the value of volume sigma squared
  inline float get_vsigsq() const { return vsigsq_; }
  //! Gets the inverse sigma squared
  inline float get_inv_sigsq() const { return inv_sigsq_; }
  //! Gets the sigma value
  inline float get_sig() const { return sig_; }
  //! Gets the value of kdist parameter
  inline float get_kdist() const { return kdist_; }
  //! Gets the value of normfac parameter
  inline float get_normfac() const { return normfac_; }
  ~RadiusDependentKernelParameters() {
    vsig_ = std::numeric_limits<float>::quiet_NaN();
    vsigsq_ = std::numeric_limits<float>::quiet_NaN();
    inv_sigsq_ = std::numeric_limits<float>::quiet_NaN();
    sig_ = std::numeric_limits<float>::quiet_NaN();
    kdist_ = std::numeric_limits<float>::quiet_NaN();
    normfac_ = std::numeric_limits<float>::quiet_NaN();
  }

 protected:
  //! vsig
  float vsig_;
  //! square of vsig
  float vsigsq_;
  //! the inverse of sigma square
  float inv_sigsq_;
  //! the sigma
  float sig_;
  //! the kernel distance (= elements for summation)
  float kdist_;
  //! normalization factor
  float normfac_;
};

IMP_VALUES(RadiusDependentKernelParameters,
           RadiusDependentKernelParametersList);

//! Calculates and stores Gaussian kernel parameters as a function
//! of a specific radius.
class IMPEMEXPORT KernelParameters {
 public:
  KernelParameters() { initialized_ = false; }

  KernelParameters(float resolution) {
    init(resolution);
    initialized_ = true;
  }

  ~KernelParameters();

  //! Sets the parameters that depend on the radius of a given particle.
  /** The other variables of the parameters
    (rsigsq,timessig,sq2pi3,inv_rsigsq,rnormfac,rkdist) must have been set.
    \param[in] radius the radius
    \return the radius based parameters
  */
  const RadiusDependentKernelParameters& set_params(float radius);

  //! Finds the precomputed parameters given a particle radius.
  /**
    \param[in] radius searching for parameters of this radius
    \param[in] eps used for numerical stability
    \note The parameters are indexes by the radius. To maintain
    numerical stability, look for a radius within +-eps from the
    queried radius.
   \note if parameters for this radius were not found, a warning is printed
         and the parameters are calculated using set_params().
  */
  const RadiusDependentKernelParameters& get_params(float radius,
                                                    float eps = 0.001);

  //! Get sigma as a function of the resolution according to the
  //! full width at half maximum criterion
  inline float get_rsig() const { return rsig_; }
  //! Get squared sigma as a function of the resolution according to the
  //! full width at half maximum criterion
  inline float get_rsigsq() const { return rsigsq_; }
  //! Get the inverse of sigma squared
  inline float get_inv_rsigsq() const { return inv_rsigsq_; }
  //! Gets the number of sigma used.
  /**
    \note We use 3, which means that 99% of the density is considered
   */
  inline float get_timessig() const { return timessig_; }
  //! Get the non-sigma portion of the Gaussian normalization factor
  inline float get_sq2pi3() const { return sq2pi3_; }
  //! Get the Gaussian normalization factor
  inline float get_rnormfac() const { return rnormfac_; }
  //! Get the length of the Gaussian (sigma*number_of_sigmas_used)
  inline float get_rkdist() const { return rkdist_; }
  //! Gets the value of lim parameter
  inline float get_lim() const { return lim_; }

  IMP_SHOWABLE_INLINE(KernelParameters, out << "rsig: " << rsig_ << std::endl;);

 protected:
  float rsig_, rsigsq_, timessig_, sq2pi3_, inv_rsigsq_, rnormfac_, rkdist_,
      lim_;
  bool initialized_;
  std::map<float, const RadiusDependentKernelParameters*> radii2params_;
  void init(float resolution);
};

IMP_VALUES(KernelParameters, KernelParametersList);

#if !defined(IMP_DOXYGEN) && !defined(SWIG)
class IMPEMEXPORT Kernel3D {
 public:
  Kernel3D() {}
  Kernel3D(const Kernel3D& other) {
    size_ = other.size_;
    dim_ext_ = other.dim_ext_;
    data_.reset(new double[size_]);
    std::copy(other.data_.get(), other.data_.get() + size_, data_.get());
  }
  Kernel3D(int size, int ext) {
    size_ = size;
    dim_ext_ = ext;
    data_.reset(new double[size_]);
    IMP_INTERNAL_CHECK(data_, "Can not allocate vector\n");
    for (int i = 0; i < size_; i++) data_[i] = 0.;
  }
  double* get_data() const { return data_.get(); }
  int get_size() const { return size_; }
  int get_extent() const { return dim_ext_; }

 protected:
  boost::scoped_array<double> data_;
  int size_;
  int dim_ext_;
};
IMPEMEXPORT
Kernel3D create_3d_gaussian(double sigma, double sigma_factor);
IMPEMEXPORT
Kernel3D create_3d_laplacian();
//! Truncate a kernel according to an input sigma
IMPEMEXPORT
Kernel3D get_truncated(double* data, int extent, double sigmap,
                       double sigma_fac);
#endif
IMPEM_END_NAMESPACE

#endif /* IMPEM_KERNEL_PARAMETERS_H */