1 | #ifndef BZ_RANDOM_DEFAULT_H |
---|
2 | #define BZ_RANDOM_DEFAULT_H |
---|
3 | |
---|
4 | #include <random/mt.h> |
---|
5 | |
---|
6 | BZ_NAMESPACE(ranlib) |
---|
7 | |
---|
8 | // Some terminology: |
---|
9 | // IRNG = Integer Random Number Generator. IRNGs generate random |
---|
10 | // integers, which are used to create floating-point random |
---|
11 | // numbers. |
---|
12 | // RNG = Random Number Generator. RNGs use IRNGs to create floating- |
---|
13 | // point random numbers following desired distributions. |
---|
14 | |
---|
15 | typedef float defaultType; |
---|
16 | |
---|
17 | // These are type tags. A RNG with sharedState shares an IRNG |
---|
18 | // with other RNGs. An RNG with independentState |
---|
19 | // contains its own IRNG. Generally, sharedState RNGs should be |
---|
20 | // used. |
---|
21 | |
---|
22 | struct sharedState { }; |
---|
23 | struct independentState { }; |
---|
24 | typedef sharedState defaultState; |
---|
25 | |
---|
26 | typedef unsigned int IRNG_int; |
---|
27 | |
---|
28 | |
---|
29 | // IRNGWrapper handles shared and independent state IRNGs. |
---|
30 | // If a class inherits from IRNGWrapper<IRNG,sharedState>, |
---|
31 | // it gets a static IRNG (i.e. the IRNG state is shared among |
---|
32 | // all RNGs); if it inherits from IRNGWrapper<IRNG,independentState>, |
---|
33 | // it gets an independent IRNG (the IRNG state is encapsulated |
---|
34 | // in the RNG, and is not shared among RNGs). |
---|
35 | |
---|
36 | template<typename IRNG, typename state> |
---|
37 | class IRNGWrapper { |
---|
38 | }; |
---|
39 | |
---|
40 | template<typename IRNG> |
---|
41 | class IRNGWrapper<IRNG,sharedState> { |
---|
42 | |
---|
43 | public: |
---|
44 | void seed(IRNG_int x) |
---|
45 | { irng_.seed(x); } |
---|
46 | |
---|
47 | typedef typename IRNG::T_state T_state; |
---|
48 | T_state getState() const { return irng_.getState(); } |
---|
49 | std::string getStateString() const { return irng_.getStateString(); } |
---|
50 | void setState(const T_state& s) { irng_.setState(s); } |
---|
51 | void setState(const std::string& s) { irng_.setState(s); } |
---|
52 | |
---|
53 | protected: |
---|
54 | static IRNG irng_; |
---|
55 | }; |
---|
56 | |
---|
57 | template<typename IRNG> |
---|
58 | IRNG IRNGWrapper<IRNG,sharedState>::irng_; |
---|
59 | |
---|
60 | template<typename IRNG> |
---|
61 | class IRNGWrapper<IRNG,independentState> { |
---|
62 | |
---|
63 | public: |
---|
64 | void seed(IRNG_int x) |
---|
65 | { irng_.seed(x); } |
---|
66 | |
---|
67 | typedef typename IRNG::T_state T_state; |
---|
68 | T_state getState() const { return irng_.getState(); } |
---|
69 | std::string getStateString() const { return irng_.getStateString(); } |
---|
70 | void setState(const T_state& s) { irng_.setState(s); } |
---|
71 | void setState(const std::string& s) { irng_.setState(s); } |
---|
72 | |
---|
73 | protected: |
---|
74 | IRNG irng_; |
---|
75 | }; |
---|
76 | |
---|
77 | // defaultIRNG is a type alias for the default Integer Random |
---|
78 | // Number Generator (IRNG). |
---|
79 | |
---|
80 | typedef MersenneTwister defaultIRNG; |
---|
81 | |
---|
82 | BZ_NAMESPACE_END |
---|
83 | |
---|
84 | #endif // BZ_RANDOM_DEFAULT_H |
---|
85 | |
---|