std::linear_congruential_engine - cppreference.com (original) (raw)

std::linear_congruential_engine

| | | | | --------------------------------------------------------------------------------------------------- | | ------------- | | template< class UIntType, UIntType a, UIntType c, UIntType m > class linear_congruential_engine; | | (since C++11) |

linear_congruential_engine is a random number engine based on Linear congruential generator (LCG).

Contents

• 1 Template parameters
• 2 Generator properties
• 3 Predefined specializations
• 4 Nested types
• 5 Data members
• 6 Member functions
  • 6.1 Construction and Seeding
  • 6.2 Generation
  • 6.3 Characteristics
• 7 Non-member functions
• 8 Example

[edit] Template parameters

When m is not zero, if a >= m or c >= m is true, the program is ill-formed.

[edit] Generator properties

The size of the states of linear_congruential_engine is 1, each of them consists of a single integer.

The actual modulus \(\scriptsize m_0\)m0 is defined as follows:

• If m is not zero, \(\scriptsize m_0\)m0 is m.
• If m is zero, \(\scriptsize m_0\)m0 is the value of std::numeric_limits<result_type>::max() plus 1 (which means \(\scriptsize m_0\)m0 need not be representable as result_type).

The transition algorithm of linear_congruential_engine is \(\scriptsize TA(x_i) = (a \cdot x_i + c)\mod m_0\)TA(xi) = (a·xi+c) mod m0.

The generation algorithm of linear_congruential_engine is \(\scriptsize GA(x_i) = (a \cdot x_i + c)\mod m_0\)GA(xi) = (a·xi+c) mod m0.

The pseudo-random number generated with the current state is also the successor state.

[edit] Predefined specializations

The following specializations define the random number engine with two commonly used parameter sets:

[edit] Nested types

[edit] Data members

[edit] Member functions

[edit] Non-member functions

[edit] Example