boost::probabilities::probability< Domain, Value, Validator > Class Template Reference

Probability quantity. More...

#include <probabilities.hpp>

List of all members.

Public Types
typedef Domain	domain_type
	Type of domain of operations.
typedef Value	value_type
	Type representing probability values.
typedef Validator	validator_type
	Type modeling ValidatorConcept for probability values.
Public Member Functions
	probability ()
	Construct a probability of unity.
template<typename T>
	probability (const T &t)
	Explicitly construct a probability.
template<typename T, typename D>
	probability (const T &t, D)
	Explicitly construct a probability from another domain.
template<typename D, typename V, typename VV>
	probability (const probability< D, V, VV > &p)
	Transform a probability from another domain.
	probability (const probability &p)
probability &	operator= (const probability &p)
void	swap (probability &p)
probability	operator+ () const
	Unary plus operator.
template<typename D>
probability< D, value_type, validator_type >	domain_cast (D) const
	Cast to another domain.
template<typename D>
value_type	value_cast (D) const
	Cast the internal value to another domain.
Mathematical assignment operators
The probability class is derived from the boost::operators classes. As a result, these mathematical assignment operators are the foundation for a complete set of natural mathematical operations. The probability class supports the full range of arithmetic operators.
template<typename D, typename V, typename VV>
probability &	operator+= (const probability< D, V, VV > &p)
	Addition assignment operator.
template<typename T>
probability &	operator+= (const T &t)
	Addition assignment operator.
template<typename D, typename V, typename VV>
probability &	operator-= (const probability< D, V, VV > &p)
	Subtraction assignment operator.
template<typename T>
probability &	operator-= (const T &t)
	Subtraction assignment operator.
template<typename D, typename V, typename VV>
probability &	operator *= (const probability< D, V, VV > &p)
	Multiplication assignment operator.
template<typename T>
probability &	operator *= (const T &t)
	Multiplication assignment operator.
template<typename D, typename V, typename VV>
probability &	operator/= (const probability< D, V, VV > &p)
	Division assignment operator.
template<typename T>
probability &	operator/= (const T &t)
	Division assignment operator.

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Detailed Description

template<typename Domain = linear_domain, typename Value = double, typename Validator = null_validator<Value>>
class boost::probabilities::probability< Domain, Value, Validator >

Probability quantity.

This class encapsulates a probability quantity, represented as the value_type template argument. Probabilities and their logarithms are encapsulated by types differing in their domains (i.e., the linear_domain versus the log_domain). In both cases, however, the same semantics apply to the same operators. For example, the multiplication operator operator*() denotes multiplication of probabilities or addition of logarithms of probabilities. This helps make the fundamental operations clearer in the code while providing an explicit means of selecting the mode of operation, for example to avoid underflow of the value_type. The consistency of semantics also makes generic algorithms possible.

In addition to providing all the natural arithmetic operators, the probability class models the following concepts.

• Default constructible.
• Copy constructible.
• Assignable.
• Swapable.
• Equality comparable
• Less than comparable
• Comparable (i.e., all comparison operators)

In order to model these concepts, however, the underlying value_type must also model most of these. In addition, the value_type must provide the exponential functions exp(), log(), and log1p(). Finally, the class provides strong exception guarrantees. For example, although an assignment may throw an exception, it will do so only if the copy constructor does. If this occurs, the original lvalue object is guarranteed to be unchanged.

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Member Typedef Documentation

template<typename Domain = linear_domain, typename Value = double, typename Validator = null_validator<Value>> typedef Domain boost::probabilities::probability< Domain, Value, Validator >::domain_type

Type of domain of operations. The domain of operations is assumed to be one of linear_domain or log_domain.

template<typename Domain = linear_domain, typename Value = double, typename Validator = null_validator<Value>> typedef Value boost::probabilities::probability< Domain, Value, Validator >::value_type

Type representing probability values. The value type should be a model of the real numbers within the closed interval [0,1].

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Constructor & Destructor Documentation

template<typename Domain = linear_domain, typename Value = double, typename Validator = null_validator<Value>> boost::probabilities::probability< Domain, Value, Validator >::probability (   )  [inline]

Construct a probability of unity. In many contexts, the most common operation on probabilities is multiplication. To simplify the accumulation of a product of probabilities, the default constructed value is the multiplicative identity.

template<typename Domain = linear_domain, typename Value = double, typename Validator = null_validator<Value>> template<typename T> boost::probabilities::probability< Domain, Value, Validator >::probability (  const T &  t  )  [inline, explicit]

Explicitly construct a probability. Parameters: t  Value of probability represented as the type T. Note that type T must be convertible to the internal representation of a probability (i.e., to the value_type).

template<typename Domain = linear_domain, typename Value = double, typename Validator = null_validator<Value>> template<typename T, typename D> boost::probabilities::probability< Domain, Value, Validator >::probability (  const T &  t, D  )  [inline]

Explicitly construct a probability from another domain. Parameters: t  Value of probability represented as the type T. Note that type T must be convertible to the internal representation of a probability (i.e., to the value_type).

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Member Function Documentation

template<typename Domain = linear_domain, typename Value = double, typename Validator = null_validator<Value>> template<typename T> probability& boost::probabilities::probability< Domain, Value, Validator >::operator *= (  const T &  t  )  [inline]

Multiplication assignment operator. Multiply a probability by a value of type T. Note that the type T must be convertible to the value_type. Furthermore, t is assumed to be in the linear domain; it will be converted to the appropriate domain as required.

template<typename Domain = linear_domain, typename Value = double, typename Validator = null_validator<Value>> template<typename T> probability& boost::probabilities::probability< Domain, Value, Validator >::operator+= (  const T &  t  )  [inline]

Addition assignment operator. Add a value of type T to a probability. Note that the type T must be convertible to the value_type. Furthermore, t is assumed to be in the linear domain; it will be converted to the appropriate domain as required.

template<typename Domain = linear_domain, typename Value = double, typename Validator = null_validator<Value>> template<typename T> probability& boost::probabilities::probability< Domain, Value, Validator >::operator-= (  const T &  t  )  [inline]

Subtraction assignment operator. Subtract a value of type T from a probability. Note that the type T must be convertible to the value_type. Furthermore, t is assumed to be in the linear domain; it will be converted to the appropriate domain as required.

template<typename Domain = linear_domain, typename Value = double, typename Validator = null_validator<Value>> template<typename T> probability& boost::probabilities::probability< Domain, Value, Validator >::operator/= (  const T &  t  )  [inline]

Division assignment operator. Divide a probability by a value of type T. Note that the type T must be convertible to the value_type. Furthermore, t is assumed to be in the linear domain; it will be converted to the appropriate domain as required.

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

• probabilities.hpp

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