Reference documentation for deal.II version GIT c545eda070 2023-01-27 00:25:02+00:00
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Public Types | Public Member Functions | Static Public Attributes | Private Attributes | List of all members
FloatingPointComparator< Number > Struct Template Reference

#include <deal.II/base/floating_point_comparator.h>

Public Types

enum class  ComparisonResult { less , equal , greater }
 
using ScalarNumber = typename ::internal::VectorizedArrayTrait< Number >::value_type
 

Public Member Functions

 FloatingPointComparator (const ScalarNumber tolerance, const bool use_absolute_tolerance=true, const std::bitset< width > &mask=std::bitset< width >().flip())
 
 FloatingPointComparator (const FloatingPointComparator &rhs)=default
 
 FloatingPointComparator (FloatingPointComparator &&rhs) noexcept=default
 
template<typename T >
bool operator() (const T &object1, const T &object2) const
 
template<typename T >
ComparisonResult compare (const std::vector< T > &v1, const std::vector< T > &v2) const
 
template<std::size_t dim, typename T >
ComparisonResult compare (const std::array< T, dim > &t1, const std::array< T, dim > &t2) const
 
template<int rank, int dim, typename T >
ComparisonResult compare (const Tensor< rank, dim, T > &t1, const Tensor< rank, dim, T > &t2) const
 
template<typename T >
ComparisonResult compare (const Table< 2, T > &t1, const Table< 2, T > &t2) const
 
ComparisonResult compare (const ScalarNumber s1, const ScalarNumber s2) const
 
ComparisonResult compare (const VectorizedArray< ScalarNumber, width > &v1, const VectorizedArray< ScalarNumber, width > &v2) const
 

Static Public Attributes

static constexpr std::size_t width
 

Private Attributes

const ScalarNumber tolerance
 
const bool use_absolute_tolerance
 
const std::bitset< widthmask
 

Detailed Description

template<typename Number>
struct FloatingPointComparator< Number >

A class that is used to compare floating point arrays (e.g. std::vector, Tensor<1,dim>, etc.). The most common use case of this comparator is for detecting arrays with the same content for the sake of compression. The idea of this class is to consider two arrays as equal if they are the same within a given tolerance. We use this comparator class within a std::map<> of the given arrays. Note that this comparison operator does not satisfy all the mathematical properties one usually wants to have (consider e.g. the numbers a=0, b=0.1, c=0.2 with tolerance 0.15; the operator gives a<c, but neither a<b? nor b<c? is satisfied). This is not a problem in the use cases for this class, but be careful when using it in other contexts.

Definition at line 44 of file floating_point_comparator.h.

Member Typedef Documentation

◆ ScalarNumber

template<typename Number >
using FloatingPointComparator< Number >::ScalarNumber = typename ::internal::VectorizedArrayTrait<Number>::value_type

Definition at line 46 of file floating_point_comparator.h.

Member Enumeration Documentation

◆ ComparisonResult

template<typename Number >
enum FloatingPointComparator::ComparisonResult
strong

An enum to decode whether a particular comparison returns less, larger, or equal. This is needed beyond the regular operator() because of efficiency reasons in nested checks as supported by this class.

Enumerator
less 
equal 
greater 

Definition at line 56 of file floating_point_comparator.h.

Constructor & Destructor Documentation

◆ FloatingPointComparator() [1/3]

template<typename Number >
FloatingPointComparator< Number >::FloatingPointComparator ( const ScalarNumber  tolerance,
const bool  use_absolute_tolerance = true,
const std::bitset< width > &  mask = std::bitset<width>().flip() 
)

Constructor.

Definition at line 139 of file floating_point_comparator.h.

◆ FloatingPointComparator() [2/3]

template<typename Number >
FloatingPointComparator< Number >::FloatingPointComparator ( const FloatingPointComparator< Number > &  rhs)
default

◆ FloatingPointComparator() [3/3]

template<typename Number >
FloatingPointComparator< Number >::FloatingPointComparator ( FloatingPointComparator< Number > &&  rhs)
defaultnoexcept

Member Function Documentation

◆ operator()()

template<typename Number >
template<typename T >
bool FloatingPointComparator< Number >::operator() ( const T &  object1,
const T &  object2 
) const

Compare two objects of the same type and return true in case the first object is less than the second one. This function calls the compare() functions below, so only types supported by compare() will work with this function.

Definition at line 155 of file floating_point_comparator.h.

◆ compare() [1/6]

template<typename Number >
template<typename T >
FloatingPointComparator< Number >::ComparisonResult FloatingPointComparator< Number >::compare ( const std::vector< T > &  v1,
const std::vector< T > &  v2 
) const

Compare two vectors of numbers (not necessarily of the same length), where vectors of different lengths are first sorted by their length and then by the entries.

Definition at line 166 of file floating_point_comparator.h.

◆ compare() [2/6]

template<typename Number >
template<std::size_t dim, typename T >
FloatingPointComparator< Number >::ComparisonResult FloatingPointComparator< Number >::compare ( const std::array< T, dim > &  t1,
const std::array< T, dim > &  t2 
) const

Compare two arrays.

Definition at line 189 of file floating_point_comparator.h.

◆ compare() [3/6]

template<typename Number >
template<int rank, int dim, typename T >
FloatingPointComparator< Number >::ComparisonResult FloatingPointComparator< Number >::compare ( const Tensor< rank, dim, T > &  t1,
const Tensor< rank, dim, T > &  t2 
) const

Compare two tensors.

Definition at line 206 of file floating_point_comparator.h.

◆ compare() [4/6]

template<typename Number >
template<typename T >
FloatingPointComparator< Number >::ComparisonResult FloatingPointComparator< Number >::compare ( const Table< 2, T > &  t1,
const Table< 2, T > &  t2 
) const

Compare two tables.

Definition at line 223 of file floating_point_comparator.h.

◆ compare() [5/6]

template<typename Number >
FloatingPointComparator< Number >::ComparisonResult FloatingPointComparator< Number >::compare ( const ScalarNumber  s1,
const ScalarNumber  s2 
) const

Compare two scalar numbers.

Definition at line 243 of file floating_point_comparator.h.

◆ compare() [6/6]

template<typename Number >
FloatingPointComparator< Number >::ComparisonResult FloatingPointComparator< Number >::compare ( const VectorizedArray< ScalarNumber, width > &  v1,
const VectorizedArray< ScalarNumber, width > &  v2 
) const

Compare two VectorizedArray instances.

Definition at line 264 of file floating_point_comparator.h.

Member Data Documentation

◆ width

template<typename Number >
constexpr std::size_t FloatingPointComparator< Number >::width
staticconstexpr

◆ tolerance

template<typename Number >
const ScalarNumber FloatingPointComparator< Number >::tolerance
private

Definition at line 129 of file floating_point_comparator.h.

◆ use_absolute_tolerance

template<typename Number >
const bool FloatingPointComparator< Number >::use_absolute_tolerance
private

Definition at line 130 of file floating_point_comparator.h.

◆ mask

template<typename Number >
const std::bitset<width> FloatingPointComparator< Number >::mask
private

Definition at line 131 of file floating_point_comparator.h.


The documentation for this struct was generated from the following file: