org.apache.mahout.math.jet.random.sampling
Class RandomSampler

java.lang.Object
  extended by org.apache.mahout.math.PersistentObject
      extended by org.apache.mahout.math.jet.random.sampling.RandomSampler
All Implemented Interfaces:
java.io.Serializable, java.lang.Cloneable

Deprecated. until unit tests are in place. Until this time, this class/interface is unsupported.

@Deprecated
public class RandomSampler
extends PersistentObject

See Also:
Serialized Form

Constructor Summary
RandomSampler(long n, long N, long low, RandomEngine randomGenerator)
          Deprecated. Constructs a random sampler that computes and delivers sorted random sets in blocks.
 
Method Summary
 java.lang.Object clone()
          Deprecated. Returns a deep copy of the receiver.
 void nextBlock(int count, long[] values, int fromIndex)
          Deprecated. Computes the next count random numbers of the sorted random set specified on instance construction and fills them into values, starting at index fromIndex.
protected static void rejectMethodD(long n, long N, int count, long low, long[] values, int fromIndex, RandomEngine randomGenerator)
          Deprecated. Efficiently computes a sorted random set of count elements from the interval [low,low+N-1].
static void sample(long n, long N, int count, long low, long[] values, int fromIndex, RandomEngine randomGenerator)
          Deprecated. Efficiently computes a sorted random set of count elements from the interval [low,low+N-1].
protected static void sampleMethodA(long n, long N, int count, long low, long[] values, int fromIndex, RandomEngine randomGenerator)
          Deprecated. Computes a sorted random set of count elements from the interval [low,low+N-1].
protected static void sampleMethodD(long n, long N, int count, long low, long[] values, int fromIndex, RandomEngine randomGenerator)
          Deprecated. Efficiently computes a sorted random set of count elements from the interval [low,low+N-1].
 
Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

RandomSampler

public RandomSampler(long n,
                     long N,
                     long low,
                     RandomEngine randomGenerator)
Deprecated. 
Constructs a random sampler that computes and delivers sorted random sets in blocks. A set block can be retrieved with method nextBlock. Successive calls to method nextBlock will deliver as many random numbers as required.

Parameters:
n - the total number of elements to choose (must be n >= 0 and n <= N).
N - the interval to choose random numbers from is [low,low+N-1].
low - the interval to choose random numbers from is [low,low+N-1]. Hint: If low==0, then random numbers will be drawn from the interval [0,N-1].
randomGenerator - a random number generator. Set this parameter to null to use the default random number generator.
Method Detail

clone

public java.lang.Object clone()
Deprecated. 
Returns a deep copy of the receiver.

Overrides:
clone in class PersistentObject

nextBlock

public void nextBlock(int count,
                      long[] values,
                      int fromIndex)
Deprecated. 
Computes the next count random numbers of the sorted random set specified on instance construction and fills them into values, starting at index fromIndex.

Numbers are filled into the specified array starting at index fromIndex to the right. The array is returned sorted ascending in the range filled with numbers.

Parameters:
count - the number of elements to be filled into values by this call (must be >= 0).
values - the array into which the random numbers are to be filled; must have a length >= count+fromIndex.
fromIndex - the first index within values to be filled with numbers (inclusive).

rejectMethodD

protected static void rejectMethodD(long n,
                                    long N,
                                    int count,
                                    long low,
                                    long[] values,
                                    int fromIndex,
                                    RandomEngine randomGenerator)
Deprecated. 
Efficiently computes a sorted random set of count elements from the interval [low,low+N-1]. Since we are talking about a random set, no element will occur more than once.

Running time is O(count), on average. Space requirements are zero.

Numbers are filled into the specified array starting at index fromIndex to the right. The array is returned sorted ascending in the range filled with numbers.

Parameters:
n - the total number of elements to choose (must be >= 0).
N - the interval to choose random numbers from is [low,low+N-1].
count - the number of elements to be filled into values by this call (must be >= 0 and <=n). Normally, you will set count=n.
low - the interval to choose random numbers from is [low,low+N-1]. Hint: If low==0, then draws random numbers from the interval [0,N-1].
values - the array into which the random numbers are to be filled; must have a length >= count+fromIndex.
fromIndex - the first index within values to be filled with numbers (inclusive).
randomGenerator - a random number generator.

sample

public static void sample(long n,
                          long N,
                          int count,
                          long low,
                          long[] values,
                          int fromIndex,
                          RandomEngine randomGenerator)
Deprecated. 
Efficiently computes a sorted random set of count elements from the interval [low,low+N-1]. Since we are talking about a random set, no element will occur more than once.

Running time is O(count), on average. Space requirements are zero.

Numbers are filled into the specified array starting at index fromIndex to the right. The array is returned sorted ascending in the range filled with numbers.

Random number generation: By default uses MersenneTwister, a very strong random number generator, much better than java.util.Random. You can also use other strong random number generators of Paul Houle's RngPack package. For example, Ranecu, Ranmar and Ranlux are strong well analyzed research grade pseudo-random number generators with known periods.

Parameters:
n - the total number of elements to choose (must be n >= 0 and n <= N).
N - the interval to choose random numbers from is [low,low+N-1].
count - the number of elements to be filled into values by this call (must be >= 0 and <=n). Normally, you will set count=n.
low - the interval to choose random numbers from is [low,low+N-1]. Hint: If low==0, then draws random numbers from the interval [0,N-1].
values - the array into which the random numbers are to be filled; must have a length >= count+fromIndex.
fromIndex - the first index within values to be filled with numbers (inclusive).
randomGenerator - a random number generator. Set this parameter to null to use the default random number generator.

sampleMethodA

protected static void sampleMethodA(long n,
                                    long N,
                                    int count,
                                    long low,
                                    long[] values,
                                    int fromIndex,
                                    RandomEngine randomGenerator)
Deprecated. 
Computes a sorted random set of count elements from the interval [low,low+N-1]. Since we are talking about a random set, no element will occur more than once.

Running time is O(N), on average. Space requirements are zero.

Numbers are filled into the specified array starting at index fromIndex to the right. The array is returned sorted ascending in the range filled with numbers.

Parameters:
n - the total number of elements to choose (must be >= 0).
N - the interval to choose random numbers from is [low,low+N-1].
count - the number of elements to be filled into values by this call (must be >= 0 and <=n). Normally, you will set count=n.
low - the interval to choose random numbers from is [low,low+N-1]. Hint: If low==0, then draws random numbers from the interval [0,N-1].
values - the array into which the random numbers are to be filled; must have a length >= count+fromIndex.
fromIndex - the first index within values to be filled with numbers (inclusive).
randomGenerator - a random number generator.

sampleMethodD

protected static void sampleMethodD(long n,
                                    long N,
                                    int count,
                                    long low,
                                    long[] values,
                                    int fromIndex,
                                    RandomEngine randomGenerator)
Deprecated. 
Efficiently computes a sorted random set of count elements from the interval [low,low+N-1]. Since we are talking about a random set, no element will occur more than once.

Running time is O(count), on average. Space requirements are zero.

Numbers are filled into the specified array starting at index fromIndex to the right. The array is returned sorted ascending in the range filled with numbers.

Parameters:
n - the total number of elements to choose (must be >= 0).
N - the interval to choose random numbers from is [low,low+N-1].
count - the number of elements to be filled into values by this call (must be >= 0 and <=n). Normally, you will set count=n.
low - the interval to choose random numbers from is [low,low+N-1]. Hint: If low==0, then draws random numbers from the interval [0,N-1].
values - the array into which the random numbers are to be filled; must have a length >= count+fromIndex.
fromIndex - the first index within values to be filled with numbers (inclusive).
randomGenerator - a random number generator.


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