Class Random¶
- Defined in File Random.h
Class Documentation¶
-
class
Random¶ Random number generator.
Mersenne Twister random number generator a C++ class Random Based on code by Makoto Matsumoto, Takuji Nishimura, and Shawn Cokus Richard J. Wagner v1.0 15 May 2003 rjwagner@writeme.com
Public Types
-
typedef unsigned long
uint32¶
Public Functions
-
Random()¶ auto-initialize with /dev/urandom or time() and clock() Do NOT use for CRYPTOGRAPHY without securely hashing several returned values together, otherwise the generator state can be learned after reading 624 consecutive values.
-
double
rand()¶ real number in [0,1]
-
double
rand(const double &n)¶ real number in [0,n]
-
double
randExc()¶ real number in [0,1)
-
double
randExc(const double &n)¶ real number in [0,n)
-
double
randDblExc()¶ real number in (0,1)
-
double
randDblExc(const double &n)¶ real number in (0,n) Pull a 32-bit integer from the generator state Every other access function simply transforms the numbers extracted here
-
uint64_t
randInt64()¶ integer in [0, 2**64 -1]. PROBABLY NOT SECURE TO USE
-
uint64_t
randInt64(const uint64_t &n)¶ integer in [0, n] for n < 2**64 -1. PROBABLY NOT SECURE TO USE
-
double
rand53()¶ Access to 53-bit random numbers (capacity of IEEE double precision)
-
double
randExponential()¶ Exponential distribution in (0,inf)
-
double
randNorm(const double &mean = 0.0, const double &variance = 1.0)¶ Normal distributed random number.
-
double
randUniform(double min, double max)¶ Uniform distribution in [min, max].
-
double
randRayleigh(double sigma)¶ Rayleigh distributed random number.
-
double
randFisher(double k)¶ Fisher distributed random number.
-
size_t
randBin(const std::vector<float> &cdf)¶ Draw a random bin from a (unnormalized) cumulative distribution function, without leading zero.
-
size_t
randBin(const std::vector<double> &cdf)¶
-
Vector3d
randVectorAroundMean(const Vector3d &meanDirection, double angle)¶ Random vector with given angular separation around mean direction.
-
Vector3d
randFisherVector(const Vector3d &meanDirection, double kappa)¶ Fisher distributed random vector.
-
Vector3d
randConeVector(const Vector3d &meanDirection, double angularRadius)¶ Uniform distributed random vector inside a cone.
-
Vector3d
randomInterpolatedPosition(const Vector3d &a, const Vector3d &b)¶ _Position vector uniformly distributed within propagation step size bin
-
double
randPowerLaw(double index, double min, double max)¶ Power-law distribution of a given differential spectral index.
-
double
randBrokenPowerLaw(double index1, double index2, double breakpoint, double min, double max)¶ Broken power-law distribution.
-
void
seed(uint32 *const bigSeed, const uint32 seedLength = N)¶ Seed the generator with an array of uint32’s There are 2^19937-1 possible initial states. This function allows all of those to be accessed by providing at least 19937 bits (with a default seed length of N = 624 uint32’s). Any bits above the lower 32 in each element are discarded. Just call seed() if you want to get array from /dev/urandom.
-
void
seed()¶ Seed the generator with an array from /dev/urandom if available Otherwise use a hash of time() and clock() values.
Protected Functions
-
void
initialize(const uint32 oneSeed)¶ Initialize generator state with seed See Knuth TAOCP Vol 2, 3rd Ed, p.106 for multiplier. In previous versions, most significant bits (MSBs) of the seed affect only MSBs of the state array. Modified 9 Jan 2002 by Makoto Matsumoto.
-
void
reload()¶ Generate N new values in state Made clearer and faster by Matthew Bellew (matthew.bellew@home.com)
Protected Static Functions
-
Random::uint32
hash(time_t t, clock_t c)¶ Get a uint32 from t and c Better than uint32(x) in case x is floating point in [0,1] Based on code by Lawrence Kirby (fred@genesis.demon.co.uk)
-
typedef unsigned long