Package smile.sort

Class FloatHeapSelect

java.lang.Object

smile.sort.FloatHeapSelect

public class FloatHeapSelect
extends Object

This class tracks the smallest values seen thus far in a stream of values. This implements a single-pass selection for large data sets. That is, we have a stream of input values, each of which we get to see only once. We want to be able to report at any time, say after n values, the i-th smallest value see so far.

Constructor Summary

Constructors

Constructor	Description
FloatHeapSelect(float[] heap)	Constructor.
FloatHeapSelect(int k)	Constructor.

Method Summary

Modifier and Type	Method	Description
void	add(float datum)	Assimilate a new value from the stream.
float	get(int i)	Returns the i-th smallest value seen so far.
float	peek()	Returns the k-th smallest value seen so far.
void	sort()	Sort the smallest values.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

FloatHeapSelect

public FloatHeapSelect(int k)

Constructor.

Parameters:

k - the heap size.

FloatHeapSelect

public FloatHeapSelect(float[] heap)

Constructor.

Parameters:

heap - the array to store smallest values to track.

Method Details

add

public void add(float datum)

Assimilate a new value from the stream.

Parameters:

datum - a new value.

peek

public float peek()

Returns the k-th smallest value seen so far.

Returns:

the k-th smallest value seen so far.

get

public float get(int i)

Returns the i-th smallest value seen so far. i = 0 returns the smallest value seen, i = 1 the second largest, ..., i = k-1 the last position tracked. Also, i must be less than the number of previous assimilated.

Parameters:

i - the ordinal index of smallest values.

Returns:

the i-th smallest value.

sort

public void sort()

Sort the smallest values.