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2019.3
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Gromacs
2019.3
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#include <gromacs/random/threefry.h>
Inheritance diagram for gmx::ThreeFry2x64Fast< internalCounterBits >: Collaboration diagram for gmx::ThreeFry2x64Fast< internalCounterBits >:ThreeFry2x64 random engine with 13 iteractions.
| internalCounterBits,default | 64. |
This class provides relatively high quality random numbers that only fail one BigCrush test, and it is a bit faster than the 20-round version. It works with two 64-bit values each for keys and counters, and is most efficient when we only need a few random values before restarting the counters with new values.
Public Member Functions | |
| ThreeFry2x64Fast (uint64_t key0=0, RandomDomain domain=RandomDomain::Other) | |
| Construct ThreeFry random engine with 2x64 key values, 13 rounds. More... | |
| ThreeFry2x64Fast (uint64_t key0, uint64_t key1) | |
| Construct ThreeFry random engine from 2x64-bit unsigned integers, 13 rounds. More... | |
| Public Member Functions inherited from gmx::ThreeFry2x64General< 13, internalCounterBits > | |
| ThreeFry2x64General (uint64_t key0=0, RandomDomain domain=RandomDomain::Other) | |
| Construct random engine with 2x64 key values. More... | |
| ThreeFry2x64General (uint64_t key0, uint64_t key1) | |
| Construct random engine from 2x64-bit unsigned integers. More... | |
| void | seed (uint64_t key0=0, RandomDomain domain=RandomDomain::Other) |
| Seed 2x64 random engine with two 64-bit key values. More... | |
| void | seed (uint64_t key0, uint64_t key1) |
| Seed random engine from 2x64-bit unsigned integers. More... | |
| void | restart (uint64_t ctr0=0, uint64_t ctr1=0) |
| Restart 2x64 random engine counter from 2 64-bit values. More... | |
| result_type | operator() () |
| Generate the next random number. More... | |
| void | discard (uint64_t n) |
| Skip next n random numbers. More... | |
| bool | operator== (const ThreeFry2x64General< rounds, internalCounterBits > &x) const |
| Return true if two ThreeFry2x64 engines are identical. More... | |
| bool | operator!= (const ThreeFry2x64General< rounds, internalCounterBits > &x) const |
| Return true of two ThreeFry2x64 engines are not identical. More... | |
Additional Inherited Members | |
| Public Types inherited from gmx::ThreeFry2x64General< 13, internalCounterBits > | |
| typedef uint64_t | result_type |
| Integer type for output. | |
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typedef std::array < result_type, 2 > | counter_type |
| Use array for counter & key states so it is allocated on the stack. | |
| Static Public Member Functions inherited from gmx::ThreeFry2x64General< 13, internalCounterBits > | |
| static constexpr result_type | min () |
| Smallest value that can be returned from random engine. | |
| static constexpr result_type | max () |
| Largest value that can be returned from random engine. | |
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inline |
Construct ThreeFry random engine with 2x64 key values, 13 rounds.
| key0 | Random seed in the form of a 64-bit unsigned value. |
| domain | Random domain. This is used to guarantee that different applications of a random engine inside the code get different streams of random numbers, without requiring the user to provide lots of random seeds. Pick a value from the RandomDomain class, or RandomDomain::Other if it is not important. In the latter case you might want to use gmx::DefaultRandomEngine instead. |
| InternalError | if the high bits needed to encode the number of counter bits are nonzero. |
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inline |
Construct ThreeFry random engine from 2x64-bit unsigned integers, 13 rounds.
This constructor assigns the raw 128 bit key data from unsigned integers. It is meant for the case when you want full control over the key, for instance to compare with reference values of the ThreeFry function during testing.
| key0 | First word of key/random seed. |
| key1 | Second word of key/random seed. |
| InternalError | if the high bits needed to encode the number of counter bits are nonzero. To test arbitrary values, use 0 internal counter bits. |
1.8.5