BornAgain  1.18.0
Simulate and fit neutron and x-ray scattering at grazing incidence
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RelativeDifferenceMetric Class Reference
Inheritance diagram for RelativeDifferenceMetric:
Collaboration diagram for RelativeDifferenceMetric:

Public Member Functions

 RelativeDifferenceMetric ()
 
RelativeDifferenceMetric * clone () const override
 
double computeFromArrays (std::vector< double > sim_data, std::vector< double > exp_data, std::vector< double > weight_factors) const override
 
double computeFromArrays (std::vector< double > sim_data, std::vector< double > exp_data, std::vector< double > uncertainties, std::vector< double > weight_factors) const override
 
double computeFromArrays (std::vector< double > sim_data, std::vector< double > exp_data, std::vector< double > weight_factors) const override
 
double computeFromArrays (std::vector< double > sim_data, std::vector< double > exp_data, std::vector< double > uncertainties, std::vector< double > weight_factors) const override
 
virtual double compute (const SimDataPair &data_pair, bool use_weights) const
 
void setNorm (std::function< double(double)> norm)
 
auto norm () const
 
virtual void transferToCPP ()
 

Private Attributes

std::function< double(double)> m_norm
 

Detailed Description

Implementation of relative difference metric.

With default L2 norm and weighting off corresponds to the formula

\[Result = \sum \frac{(I - D)^2}{(I + D)^2}\]

where $I$ is the simulated intensity, $D$ - experimental data. If weighting is on, falls back to the standard $\chi^2$ metric.

Definition at line 167 of file ObjectiveMetric.h.

Constructor & Destructor Documentation

◆ RelativeDifferenceMetric()

RelativeDifferenceMetric::RelativeDifferenceMetric ( )

Definition at line 196 of file ObjectiveMetric.cpp.

196 : Chi2Metric() {}

Member Function Documentation

◆ clone()

RelativeDifferenceMetric * RelativeDifferenceMetric::clone ( ) const
overridevirtual

Reimplemented from Chi2Metric.

Definition at line 198 of file ObjectiveMetric.cpp.

199 {
200  return copyMetric(*this);
201 }
anonymous_namespace{ObjectiveMetric.cpp}::copyMetric
T * copyMetric(const T &metric)
Definition: ObjectiveMetric.cpp:28

References anonymous_namespace{ObjectiveMetric.cpp}::copyMetric().

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◆ computeFromArrays() [1/4]

double RelativeDifferenceMetric::computeFromArrays ( std::vector< double >  sim_data,
std::vector< double >  exp_data,
std::vector< double >  weight_factors 
) const
overridevirtual

Computes metric value from data arrays.

Negative values in exp_data are ignored as well as non-positive weight_factors. All arrays involved in the computation must be of the same size.

Parameters
sim_dataarray with simulated intensities.
exp_dataarray with intensity values obtained from an experiment.
weight_factorsuser-defined weighting factors. Used linearly, no matter which norm is chosen.

Reimplemented from Chi2Metric.

Definition at line 203 of file ObjectiveMetric.cpp.

206 {
207  checkIntegrity(sim_data, exp_data, weight_factors);
208 
209  double result = 0.0;
210  auto norm_fun = norm();
211  for (size_t i = 0, sim_size = sim_data.size(); i < sim_size; ++i) {
212  if (weight_factors[i] <= 0.0 || exp_data[i] < 0.0)
213  continue;
214  const double sim_val = std::max(double_min, sim_data[i]);
215  const double exp_val = std::max(double_min, exp_data[i]);
216  result += norm_fun((exp_val - sim_val) / (exp_val + sim_val)) * weight_factors[i];
217  }
218 
219  return std::isfinite(result) ? result : double_max;
220 }
ObjectiveMetric::norm
auto norm() const
Returns a copy of the normalization function used.
Definition: ObjectiveMetric.h:63
anonymous_namespace{ObjectiveMetric.cpp}::double_min
const double double_min
Definition: ObjectiveMetric.cpp:25
anonymous_namespace{ObjectiveMetric.cpp}::double_max
const double double_max
Definition: ObjectiveMetric.cpp:24
anonymous_namespace{ObjectiveMetric.cpp}::checkIntegrity
void checkIntegrity(const std::vector< double > &sim_data, const std::vector< double > &exp_data, const std::vector< double > &uncertainties, const std::vector< double > &weight_factors)
Definition: ObjectiveMetric.cpp:48

References anonymous_namespace{ObjectiveMetric.cpp}::checkIntegrity(), anonymous_namespace{ObjectiveMetric.cpp}::double_max, anonymous_namespace{ObjectiveMetric.cpp}::double_min, and ObjectiveMetric::norm().

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◆ computeFromArrays() [2/4]

double Chi2Metric::computeFromArrays
override

Computes metric value from data arrays.

Negative values in exp_data are ignored as well as non-positive weight_factors and uncertainties. All arrays involved in the computation must be of the same size.

Parameters
sim_dataarray with simulated intensities.
exp_dataarray with intensity values obtained from an experiment.
uncertaintiesarray with experimental data uncertainties.
weight_factorsuser-defined weighting factors. Used linearly, no matter which norm is chosen.

Definition at line 87 of file ObjectiveMetric.cpp.

92 {
93  checkIntegrity(sim_data, exp_data, uncertainties, weight_factors);
94 
95  double result = 0.0;
96  auto norm_fun = norm();
97  for (size_t i = 0, sim_size = sim_data.size(); i < sim_size; ++i)
98  if (exp_data[i] >= 0.0 && weight_factors[i] > 0.0 && uncertainties[i] > 0.0)
99  result += norm_fun((exp_data[i] - sim_data[i]) / uncertainties[i]) * weight_factors[i];
100 
101  return std::isfinite(result) ? result : double_max;
102 }

◆ computeFromArrays() [3/4]

double Chi2Metric::computeFromArrays
override

Computes metric value from data arrays.

Negative values in exp_data are ignored as well as non-positive weight_factors. All arrays involved in the computation must be of the same size.

Parameters
sim_dataarray with simulated intensities.
exp_dataarray with intensity values obtained from an experiment.
weight_factorsuser-defined weighting factors. Used linearly, no matter which norm is chosen.

Definition at line 98 of file ObjectiveMetric.cpp.

106 {
107  checkIntegrity(sim_data, exp_data, weight_factors);
108 
109  auto norm_fun = norm();
110  double result = 0.0;
111  for (size_t i = 0, sim_size = sim_data.size(); i < sim_size; ++i)
112  if (exp_data[i] >= 0.0 && weight_factors[i] > 0.0)
113  result += norm_fun(exp_data[i] - sim_data[i]) * weight_factors[i];
114 
115  return std::isfinite(result) ? result : double_max;
116 }

◆ computeFromArrays() [4/4]

double Chi2Metric::computeFromArrays ( std::vector< double >  sim_data,
std::vector< double >  exp_data,
std::vector< double >  uncertainties,
std::vector< double >  weight_factors 
) const
overridevirtualinherited

Computes metric value from data arrays.

Negative values in exp_data are ignored as well as non-positive weight_factors and uncertainties. All arrays involved in the computation must be of the same size.

Parameters
sim_dataarray with simulated intensities.
exp_dataarray with intensity values obtained from an experiment.
uncertaintiesarray with experimental data uncertainties.
weight_factorsuser-defined weighting factors. Used linearly, no matter which norm is chosen.

Implements ObjectiveMetric.

Definition at line 89 of file ObjectiveMetric.cpp.

92 {
93  checkIntegrity(sim_data, exp_data, uncertainties, weight_factors);
94 
95  double result = 0.0;
96  auto norm_fun = norm();
97  for (size_t i = 0, sim_size = sim_data.size(); i < sim_size; ++i)
98  if (exp_data[i] >= 0.0 && weight_factors[i] > 0.0 && uncertainties[i] > 0.0)
99  result += norm_fun((exp_data[i] - sim_data[i]) / uncertainties[i]) * weight_factors[i];
100 
101  return std::isfinite(result) ? result : double_max;
102 }

References anonymous_namespace{ObjectiveMetric.cpp}::checkIntegrity(), and ObjectiveMetric::norm().

Referenced by RQ4Metric::compute().

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◆ compute()

double ObjectiveMetric::compute ( const SimDataPair &  data_pair,
bool  use_weights 
) const
virtualinherited

Computes metric value from SimDataPair object.

Calls computeFromArrays internally.

Parameters
data_pairSimDataPair object. Can optionally contain data uncertainties
use_weightsboolean, defines if data uncertainties should be taken into account

Reimplemented in RQ4Metric.

Definition at line 61 of file ObjectiveMetric.cpp.

62 {
63  if (use_weights && !data_pair.containsUncertainties())
64  throw std::runtime_error("Error in ObjectiveMetric::compute: the metric is weighted, but "
65  "the simulation-data pair does not contain uncertainties");
66 
67  if (use_weights)
68  return computeFromArrays(data_pair.simulation_array(), data_pair.experimental_array(),
69  data_pair.uncertainties_array(), data_pair.user_weights_array());
70  else
71  return computeFromArrays(data_pair.simulation_array(), data_pair.experimental_array(),
72  data_pair.user_weights_array());
73 }
ObjectiveMetric::computeFromArrays
virtual double computeFromArrays(std::vector< double > sim_data, std::vector< double > exp_data, std::vector< double > uncertainties, std::vector< double > weight_factors) const =0
Computes metric value from data arrays.
SimDataPair::experimental_array
std::vector< double > experimental_array() const
Returns the flattened experimental data cut to the ROI area.
Definition: SimDataPair.cpp:146
SimDataPair::user_weights_array
std::vector< double > user_weights_array() const
Returns a flat array of user weights cut to the ROI area.
Definition: SimDataPair.cpp:167
SimDataPair::uncertainties_array
std::vector< double > uncertainties_array() const
Returns the flattened experimental uncertainties cut to the ROI area.
Definition: SimDataPair.cpp:160
SimDataPair::simulation_array
std::vector< double > simulation_array() const
Returns the flattened simulated intensities cut to the ROI area.
Definition: SimDataPair.cpp:153
SimDataPair::containsUncertainties
bool containsUncertainties() const
Definition: SimDataPair.cpp:81

References ObjectiveMetric::computeFromArrays(), SimDataPair::containsUncertainties(), SimDataPair::experimental_array(), SimDataPair::simulation_array(), SimDataPair::uncertainties_array(), and SimDataPair::user_weights_array().

Referenced by RQ4Metric::compute().

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◆ setNorm()

void ObjectiveMetric::setNorm ( std::function< double(double)>  norm)
inherited

Definition at line 75 of file ObjectiveMetric.cpp.

76 {
77  m_norm = std::move(norm);
78 }
ObjectiveMetric::m_norm
std::function< double(double)> m_norm
Definition: ObjectiveMetric.h:66

References ObjectiveMetric::m_norm, and ObjectiveMetric::norm().

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◆ norm()

auto ObjectiveMetric::norm ( ) const
inlineinherited

Returns a copy of the normalization function used.

Definition at line 63 of file ObjectiveMetric.h.

63 { return m_norm; }

References ObjectiveMetric::m_norm.

Referenced by Chi2Metric::computeFromArrays(), LogMetric::computeFromArrays(), PoissonLikeMetric::computeFromArrays(), computeFromArrays(), and ObjectiveMetric::setNorm().

◆ transferToCPP()

virtual void ICloneable::transferToCPP ( )
inlinevirtualinherited

Used for Python overriding of clone (see swig/tweaks.py)

Definition at line 34 of file ICloneable.h.

Member Data Documentation

◆ m_norm

std::function<double(double)> ObjectiveMetric::m_norm
privateinherited

Definition at line 66 of file ObjectiveMetric.h.

Referenced by ObjectiveMetric::norm(), and ObjectiveMetric::setNorm().

The documentation for this class was generated from the following files: