public void Sample(int n, Boolean withReplacement, RandomEngine randomGenerator, Cern.Colt.Buffer.DoubleBuffer buffer)
{
if (randomGenerator == null)
{
randomGenerator = Cern.Jet.Random.Uniform.MakeDefaultGenerator();
}
buffer.Clear();
if (!withReplacement)
{ // without
if (n > Size)
{
throw new ArgumentException("n must be less than or equal to Size()");
}
Cern.Jet.Random.Sampling.RandomSamplingAssistant sampler = new Cern.Jet.Random.Sampling.RandomSamplingAssistant(n, Size, randomGenerator);
for (int i = n; --i >= 0;)
{
if (sampler.SampleNextElement())
{
buffer.Add(this.Elements[i]);
}
}
}
else
{ // with
Cern.Jet.Random.Uniform uniform = new Cern.Jet.Random.Uniform(randomGenerator);
int s = Size;
for (int i = n; --i >= 0;)
{
buffer.Add(this.Elements[uniform.NextIntFromTo(0, s - 1)]);
}
buffer.Flush();
}
}
/// <summary>
/// Randomly permutes the part of the receiver between <code>from</code> (inclusive) and <code>to</code> (inclusive)d
/// <summary>
/// <param name="from">the index of the first element (inclusive) to be permuted.</param>
/// <param name="to">the index of the last element (inclusive) to be permuted.</param>
/// <exception cref="IndexOutOfRangeException">index is out of range (<i>Size>0 && (from<0 || from>to || to>=Size)</i>). </exception>
public override void ShuffleFromTo(int from, int to)
{
// overridden for performance only.
if (Size == 0)
{
return;
}
CheckRangeFromTo(from, to, Size);
var gen = new Cern.Jet.Random.Uniform(new Cern.Jet.Random.Engine.DRand(new DateTime()));
double tmpElement;
double[] theElements = _elements;
int random;
for (int i = from; i < to; i++)
{
random = gen.NextIntFromTo(i, to);
//swap(i, random)
tmpElement = theElements[random];
theElements[random] = theElements[i];
theElements[i] = tmpElement;
}
}
/// <summary>
/// Randomly permutes the part of the receiver between <code>from</code> (inclusive) and <code>to</code> (inclusive)d
/// <summary>
/// <param name="from">the index of the first element (inclusive) to be permuted.</param>
/// <param name="to">the index of the last element (inclusive) to be permuted.</param>
/// <exception cref="IndexOutOfRangeException">index is out of range (<i>_size()>0 && (from<0 || from>to || to>=_size())</i>). </exception>
public override void ShuffleFromTo(int from, int to)
{
CheckRangeFromTo(from, to, Size);
Cern.Jet.Random.Uniform gen = new Cern.Jet.Random.Uniform(Cern.Jet.Random.Uniform.MakeDefaultGenerator());
for (int i = from; i < to; i++)
{
int random = gen.NextIntFromTo(i, to);
//swap(i, random)
short tmpElement = GetQuick(random);
SetQuick(random, GetQuick(i));
SetQuick(i, tmpElement);
}
}
/// <summary>
/// Randomly permutes the part of the receiver between <code>from</code> (inclusive) and <code>to</code> (inclusive)d
/// <summary>
/// <param name="from">the index of the first element (inclusive) to be permuted.</param>
/// <param name="to">the index of the last element (inclusive) to be permuted.</param>
/// <exception cref="IndexOutOfRangeException">index is out of range (<i>_size>0 && (from<0 || from>to || to>=_size)</i>). </exception>
public override void ShuffleFromTo(int from, int to)
{
CheckRangeFromTo(from, to, _size);
Cern.Jet.Random.Uniform gen = new Cern.Jet.Random.Uniform(new Cern.Jet.Random.Engine.DRand(new DateTime()));
for (int i = from; i < to; i++)
{
int random = gen.NextIntFromTo(i, to);
//swap(i, random)
Boolean tmpElement = GetQuick(random);
SetQuick(random, GetQuick(i));
SetQuick(i, tmpElement);
}
}
public static int[] Permutation(long p, int N)
{
if (p < 1)
{
throw new ArgumentException(Cern.LocalizedResources.Instance().Exception_PermutationsAreEnumerated);
}
if (N < 0)
{
throw new ArgumentException(Cern.LocalizedResources.Instance().Exception_MustSatisfyNGraterThanOrEqualsToZero);
}
int[] permutation = new int[N];
if (N > 20)
{ // factorial(21) would overflow 64-bit long)
// Simply make a list (0,1,..N-1) and randomize it, seeded with "p"d
// Note that this is perhaps not what you want...
for (int i = N; --i >= 0;)
{
permutation[i] = i;
}
var gen = new Cern.Jet.Random.Uniform(new Cern.Jet.Random.Engine.MersenneTwister((int)p));
for (int i = 0; i < N - 1; i++)
{
int random = gen.NextIntFromTo(i, N - 1);
//swap(i, random)
int tmp = permutation[random];
permutation[random] = permutation[i];
permutation[i] = tmp;
}
return(permutation);
}
// the normal case - exact enumeration
if (p > Cern.Jet.Math.Arithmetic.LongFactorial(N))
{
throw new ArgumentException(Cern.LocalizedResources.Instance().Exception_NTooLarge);
}
var tmp2 = new int[N];
for (int i = 1; i <= N; i++)
{
tmp2[i - 1] = i;
}
long io = p - 1;
for (int M = N - 1; M >= 1; M--)
{
long fac = Cern.Jet.Math.Arithmetic.LongFactorial(M);
int i = ((int)(io / fac)) + 1;
io = io % fac;
permutation[N - M - 1] = tmp2[i - 1];
for (int j = i; j <= M; j++)
{
tmp2[j - 1] = tmp2[j];
}
}
if (N > 0)
{
permutation[N - 1] = tmp2[0];
}
for (int i = N; --i >= 0;)
{
permutation[i] = permutation[i] - 1;
}
return(permutation);
}
public static int[] permutation(long p, int N)
{
if (p < 1)
{
throw new ArgumentException("Permutations are enumerated 1 .d N!");
}
if (N < 0)
{
throw new ArgumentException("Must satisfy N >= 0");
}
int[] permutation = new int[N];
if (N > 20)
{ // factorial(21) would overflow 64-bit long)
// Simply make a list (0,1,..N-1) and randomize it, seeded with "p"d
// Note that this is perhaps not what you want...
for (int i = N; --i >= 0;)
{
permutation[i] = i;
}
var gen = new Cern.Jet.Random.Uniform(new Cern.Jet.Random.Engine.MersenneTwister((int)p));
for (int i = 0; i < N - 1; i++)
{
int random = gen.NextIntFromTo(i, N - 1);
//swap(i, random)
int tmp = permutation[random];
permutation[random] = permutation[i];
permutation[i] = tmp;
}
return(permutation);
}
// the normal case - exact enumeration
if (p > Cern.Jet.Math.Arithmetic.LongFactorial(N))
{
throw new ArgumentException("N too large (a sequence of N elements only has N! permutations).");
}
var tmp2 = new int[N];
for (int i = 1; i <= N; i++)
{
tmp2[i - 1] = i;
}
long io = p - 1;
for (int M = N - 1; M >= 1; M--)
{
long fac = Cern.Jet.Math.Arithmetic.LongFactorial(M);
int i = ((int)(io / fac)) + 1;
io = io % fac;
permutation[N - M - 1] = tmp2[i - 1];
for (int j = i; j <= M; j++)
{
tmp2[j - 1] = tmp2[j];
}
}
if (N > 0)
{
permutation[N - 1] = tmp2[0];
}
for (int i = N; --i >= 0;)
{
permutation[i] = permutation[i] - 1;
}
return(permutation);
}
