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Standardized the generate method of the marsenne twister random generator in order to get also a unsigned capped random generation (like all the other generate() of the other random generators)

This commit is contained in:
Paolo Cignoni 2014-04-17 08:19:06 +00:00
parent c085b7d6ba
commit 7dbcb078e5
1 changed files with 215 additions and 211 deletions
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426
vcg/math/random_generator.h
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@ -40,29 +40,29 @@ class RandomGenerator
// construction // construction
public: public:
RandomGenerator(){} RandomGenerator(){}
virtual ~RandomGenerator() virtual ~RandomGenerator()
{} {}
// public methods // public methods
public: public:
/// (Re-)initialize with a given seed. /// (Re-)initialize with a given seed.
virtual void initialize(unsigned int seed)=0; virtual void initialize(unsigned int seed)=0;
/// Return a random number in the given range (note that not all the RNG can handle a given limit). /// Return a random number in the given range (note that not all the RNG can handle a given limit).
virtual unsigned int generate(unsigned int limit)=0; virtual unsigned int generate(unsigned int limit)=0;
/// Return a random number in the [0,1) real interval. /// Return a random number in the [0,1) real interval.
virtual double generate01()=0; virtual double generate01()=0;
/// Returns a random number in the [0,1] real interval. /// Returns a random number in the [0,1] real interval.
virtual double generate01closed()=0; virtual double generate01closed()=0;
/// Generates a random number in the (0,1) real interval. /// Generates a random number in the (0,1) real interval.
virtual double generate01open()=0; virtual double generate01open()=0;
virtual double generateRange(double minV, double maxV) { return minV+(maxV-minV)*generate01(); } virtual double generateRange(double minV, double maxV) { return minV+(maxV-minV)*generate01(); }
}; };
@ -81,9 +81,9 @@ vcg::Point3<ScalarType> GenerateBarycentricUniform(GeneratorType &rnd)
interp[2] = 1.0 - interp[2]; interp[2] = 1.0 - interp[2];
} }
assert(interp[1] + interp[2] <= 1.0); assert(interp[1] + interp[2] <= 1.0);
interp[0]=1.0-(interp[1] + interp[2]); interp[0]=1.0-(interp[1] + interp[2]);
return interp; return interp;
} }
/// \brief Generate a random point insidie a box with uniform distribution /// \brief Generate a random point insidie a box with uniform distribution
@ -159,80 +159,80 @@ class SubtractiveRingRNG : public RandomGenerator
// private data member // private data member
private: private:
// Subtractive Ring RNG status variables // Subtractive Ring RNG status variables
unsigned int _M_table[55]; unsigned int _M_table[55];
size_t _M_index1; size_t _M_index1;
size_t _M_index2; size_t _M_index2;
// construction // construction
public: public:
// ctor // ctor
SubtractiveRingRNG(int default_seed=161803398u) SubtractiveRingRNG(int default_seed=161803398u)
{ {
initialize(default_seed); initialize(default_seed);
} }
virtual ~SubtractiveRingRNG() virtual ~SubtractiveRingRNG()
{} {}
// public methods // public methods
public: public:
/// (Re-)initialize with a given seed. /// (Re-)initialize with a given seed.
void initialize(unsigned int seed) void initialize(unsigned int seed)
{ {
unsigned int __k = 1; unsigned int __k = 1;
_M_table[54] = seed; _M_table[54] = seed;
size_t __i; size_t __i;
for (__i = 0; __i < 54; __i++) for (__i = 0; __i < 54; __i++)
{ {
size_t __ii = (21 * (__i + 1) % 55) - 1; size_t __ii = (21 * (__i + 1) % 55) - 1;
_M_table[__ii] = __k; _M_table[__ii] = __k;
__k = seed - __k; __k = seed - __k;
seed = _M_table[__ii]; seed = _M_table[__ii];
} }
for (int __loop = 0; __loop < 4; __loop++) for (int __loop = 0; __loop < 4; __loop++)
{ {
for (__i = 0; __i < 55; __i++) for (__i = 0; __i < 55; __i++)
_M_table[__i] = _M_table[__i] - _M_table[(1 + __i + 30) % 55]; _M_table[__i] = _M_table[__i] - _M_table[(1 + __i + 30) % 55];
} }
_M_index1 = 0; _M_index1 = 0;
_M_index2 = 31; _M_index2 = 31;
} }
/// Return a random number in the given range (limit) using the Subtractive Ring method. /// Return a random number in the given range (limit) using the Subtractive Ring method.
unsigned int generate(unsigned int limit= 0xffffffffu) unsigned int generate(unsigned int limit= 0xffffffffu)
{ {
_M_index1 = (_M_index1 + 1) % 55; _M_index1 = (_M_index1 + 1) % 55;
_M_index2 = (_M_index2 + 1) % 55; _M_index2 = (_M_index2 + 1) % 55;
_M_table[_M_index1] = _M_table[_M_index1] - _M_table[_M_index2]; _M_table[_M_index1] = _M_table[_M_index1] - _M_table[_M_index2];
return _M_table[_M_index1] % limit; return _M_table[_M_index1] % limit;
} }
/// Return a random number in the [0,1) real interval using the Subtractive Ring method. /// Return a random number in the [0,1) real interval using the Subtractive Ring method.
double generate01() double generate01()
{ {
const unsigned int lmt = 0xffffffffu; const unsigned int lmt = 0xffffffffu;
unsigned int number = generate(lmt); unsigned int number = generate(lmt);
return static_cast<double>(number) / static_cast<double>(lmt); return static_cast<double>(number) / static_cast<double>(lmt);
} }
/// Returns a random number in the [0,1] real interval using the Subtractive Ring method. /// Returns a random number in the [0,1] real interval using the Subtractive Ring method.
double generate01closed() double generate01closed()
{ {
const unsigned int lmt = 0xffffffffu; const unsigned int lmt = 0xffffffffu;
unsigned int number = generate(lmt); unsigned int number = generate(lmt);
return static_cast<double>(number) / static_cast<double>(0xfffffffEu); return static_cast<double>(number) / static_cast<double>(0xfffffffEu);
} }
/// Generates a random number in the (0,1) real interval using the Subtractive Ring method. /// Generates a random number in the (0,1) real interval using the Subtractive Ring method.
double generate01open() double generate01open()
{ {
const unsigned int lmt = 0xffffffffu; const unsigned int lmt = 0xffffffffu;
unsigned int number = generate(lmt); unsigned int number = generate(lmt);
return (static_cast<double>(number) + 0.5) * (1.0/static_cast<double>(lmt)); return (static_cast<double>(number) + 0.5) * (1.0/static_cast<double>(lmt));
} }
}; };
@ -253,174 +253,178 @@ class MarsenneTwisterRNG : public RandomGenerator
// definitions // definitions
private: private:
static const int N = 624; static const int N = 624;
static const int M = 397; static const int M = 397;
static const unsigned int MATRIX_A = 0x9908b0dfu; // constant vector a static const unsigned int MATRIX_A = 0x9908b0dfu; // constant vector a
static const unsigned int UPPER_MASK = 0x80000000u; // most significant w-r bits static const unsigned int UPPER_MASK = 0x80000000u; // most significant w-r bits
static const unsigned int LOWER_MASK = 0x7fffffffu; // least significant r bits static const unsigned int LOWER_MASK = 0x7fffffffu; // least significant r bits
// private data member // private data member
private: private:
// Improved Marsenne-Twister RNG status variables // Improved Marsenne-Twister RNG status variables
unsigned int mt[N]; // the array for the state vector unsigned int mt[N]; // the array for the state vector
int mti; int mti;
// construction // construction
public: public:
// ctor // ctor
MarsenneTwisterRNG() MarsenneTwisterRNG()
{ {
initialize(5489u); initialize(5489u);
} }
MarsenneTwisterRNG(unsigned int seed) MarsenneTwisterRNG(unsigned int seed)
{ {
initialize(seed); initialize(seed);
} }
virtual ~MarsenneTwisterRNG() virtual ~MarsenneTwisterRNG()
{} {}
// public methods // public methods
public: public:
/// (Re-)initialize with the given seed. /// (Re-)initialize with the given seed.
void initialize(unsigned int seed) void initialize(unsigned int seed)
{ {
mt[0]= seed & 0xffffffffu; mt[0]= seed & 0xffffffffu;
for (mti=1; mti<N; mti++) for (mti=1; mti<N; mti++)
{ {
mt[mti] = (1812433253u * (mt[mti-1] ^ (mt[mti-1] >> 30)) + mti); mt[mti] = (1812433253u * (mt[mti-1] ^ (mt[mti-1] >> 30)) + mti);
/* See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier. */ /* See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier. */
/* In the previous versions, MSBs of the seed affect */ /* In the previous versions, MSBs of the seed affect */
/* only MSBs of the array mt[]. */ /* only MSBs of the array mt[]. */
/* 2002/01/09 modified by Makoto Matsumoto */ /* 2002/01/09 modified by Makoto Matsumoto */
mt[mti] &= 0xffffffffu; mt[mti] &= 0xffffffffu;
/* for >32 bit machines */ /* for >32 bit machines */
} }
} }
/** /**
* Initialize by an array with array-length. * Initialize by an array with array-length.
* *
* init_key is the array for initializing keys * init_key is the array for initializing keys
* key_length is its length * key_length is its length
*/ */
void initializeByArray(unsigned int init_key[], int key_length) void initializeByArray(unsigned int init_key[], int key_length)
{ {
int i, j, k; int i, j, k;
initialize(19650218u); initialize(19650218u);
i=1; j=0; i=1; j=0;
k = (N>key_length ? N : key_length); k = (N>key_length ? N : key_length);
for (; k; k--) for (; k; k--)
{ {
mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 30)) * 1664525u)) + init_key[j] + j; /* non linear */ mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 30)) * 1664525u)) + init_key[j] + j; /* non linear */
mt[i] &= 0xffffffffu; /* for WORDSIZE > 32 machines */ mt[i] &= 0xffffffffu; /* for WORDSIZE > 32 machines */
i++; j++; i++; j++;
if (i>=N) if (i>=N)
{ {
mt[0] = mt[N-1]; mt[0] = mt[N-1];
i=1; i=1;
} }
if (j>=key_length) j=0; if (j>=key_length) j=0;
} }
for (k=N-1; k; k--) for (k=N-1; k; k--)
{ {
mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 30)) * 1566083941u)) - i; /* non linear */ mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 30)) * 1566083941u)) - i; /* non linear */
mt[i] &= 0xffffffffu; /* for WORDSIZE > 32 machines */ mt[i] &= 0xffffffffu; /* for WORDSIZE > 32 machines */
i++; i++;
if (i>=N) if (i>=N)
{ {
mt[0] = mt[N-1]; mt[0] = mt[N-1];
i=1; i=1;
} }
} }
mt[0] = 0x80000000u; /* MSB is 1; assuring non-zero initial array */ mt[0] = 0x80000000u; /* MSB is 1; assuring non-zero initial array */
} }
/** unsigned int generate(unsigned int limit)
* Return a random number in the [0,0xffffffff] interval using the improved Marsenne Twister algorithm. {
* return generate()%limit;
* NOTE: Limit is not considered, the interval is fixed. }
*/
unsigned int generate(unsigned int /*limit*/)
{
unsigned int y;
static unsigned int mag01[2]={0x0u, MATRIX_A};
/* mag01[x] = x * MATRIX_A for x=0,1 */
if (mti >= N) // generate N words at one time /**
{ * Return a random number in the [0,0xffffffff] interval using the improved Marsenne Twister algorithm.
int kk; *
* NOTE: Limit is not considered, the interval is fixed.
*/
unsigned int generate()
{
unsigned int y;
static unsigned int mag01[2]={0x0u, MATRIX_A};
/* mag01[x] = x * MATRIX_A for x=0,1 */
for (kk=0;kk<N-M;kk++) if (mti >= N) // generate N words at one time
{ {
y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK); int kk;
mt[kk] = mt[kk+M] ^ (y >> 1) ^ mag01[y & 0x1u];
}
for (;kk<N-1;kk++) for (kk=0;kk<N-M;kk++)
{ {
y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK); y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK);
mt[kk] = mt[kk+(M-N)] ^ (y >> 1) ^ mag01[y & 0x1u]; mt[kk] = mt[kk+M] ^ (y >> 1) ^ mag01[y & 0x1u];
} }
y = (mt[N-1]&UPPER_MASK)|(mt[0]&LOWER_MASK); for (;kk<N-1;kk++)
mt[N-1] = mt[M-1] ^ (y >> 1) ^ mag01[y & 0x1u]; {
y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK);
mt[kk] = mt[kk+(M-N)] ^ (y >> 1) ^ mag01[y & 0x1u];
}
mti = 0; y = (mt[N-1]&UPPER_MASK)|(mt[0]&LOWER_MASK);
} mt[N-1] = mt[M-1] ^ (y >> 1) ^ mag01[y & 0x1u];
y = mt[mti++]; mti = 0;
}
/* Tempering */ y = mt[mti++];
y ^= (y >> 11);
y ^= (y << 7) & 0x9d2c5680u;
y ^= (y << 15) & 0xefc60000u;
y ^= (y >> 18);
return y; /* Tempering */
} y ^= (y >> 11);
y ^= (y << 7) & 0x9d2c5680u;
y ^= (y << 15) & 0xefc60000u;
y ^= (y >> 18);
/// Returns a random number in the [0,1] real interval using the improved Marsenne-Twister. return y;
double generate01closed() }
{
return generate(0)*(1.0/4294967295.0);
}
/// Returns a random number in the [0,1) real interval using the improved Marsenne-Twister. /// Returns a random number in the [0,1] real interval using the improved Marsenne-Twister.
double generate01() double generate01closed()
{ {
return generate(0)*(1.0/4294967296.0); return generate()*(1.0/4294967295.0);
} }
/// Generates a random number in the (0,1) real interval using the improved Marsenne-Twister. /// Returns a random number in the [0,1) real interval using the improved Marsenne-Twister.
double generate01open() double generate01()
{ {
return (((double)generate(0)) + 0.5)*(1.0/4294967296.0); return generate()*(1.0/4294967296.0);
} }
/// Generate a random triple of baricentric coords /// Generates a random number in the (0,1) real interval using the improved Marsenne-Twister.
template <class PointType> double generate01open()
void generateBarycentric(PointType &p){ {
p[1] = this->generate01(); return (((double)generate()) + 0.5)*(1.0/4294967296.0);
p[2] = this->generate01(); }
if(p[1] + p[2] > 1.0){ /// Generate a random triple of baricentric coords
p[1] = 1.0 - p[1]; template <class PointType>
p[2] = 1.0 - p[2]; void generateBarycentric(PointType &p){
} p[1] = this->generate01();
p[0]=1.0-(p[1] + p[2]); p[2] = this->generate01();
}
};
if(p[1] + p[2] > 1.0){
p[1] = 1.0 - p[1];
p[2] = 1.0 - p[2];
}
p[0]=1.0-(p[1] + p[2]);
}
}; // end class MarsenneTwisterRNG
/* Returns a value with normal distribution with mean m, standard deviation s /* Returns a value with normal distribution with mean m, standard deviation s
* *