org.apache.lucene.facet.search.sampling
Class SamplingParams

java.lang.Object
  org.apache.lucene.facet.search.sampling.SamplingParams

public class SamplingParams
extends Object

Parameters for sampling, dictating whether sampling is to take place and how.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Field Summary

static int	DEFAULT_MAX_SAMPLE_SIZE Default maximum size of sample.
static int	DEFAULT_MIN_SAMPLE_SIZE Default minimum size of sample.
static double	DEFAULT_OVERSAMPLE_FACTOR Default factor by which more results are requested over the sample set.
static double	DEFAULT_SAMPLE_RATIO Default ratio between size of sample to original size of document set.
static int	DEFAULT_SAMPLING_THRESHOLD Default sampling threshold, if number of results is less than this number - no sampling will take place

Constructor Summary

SamplingParams()

Method Summary

int	getMaxSampleSize() Return the maxSampleSize.
int	getMinSampleSize() Return the minSampleSize.
double	getOversampleFactor() Return the oversampleFactor.
double	getSampleRatio()
int	getSamplingThreshold() Return the samplingThreshold.
void	setMaxSampleSize(int maxSampleSize)
void	setMinSampleSize(int minSampleSize)
void	setOversampleFactor(double oversampleFactor)
void	setSampingThreshold(int sampingThreshold) Set a sampling-threshold
void	setSampleRatio(double sampleRatio)
boolean	validate() Check validity of sampling settings, making sure that minSampleSize <= maxSampleSize <= samplingThreshold 0 < samplingRatio <= 1

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_OVERSAMPLE_FACTOR

public static final double DEFAULT_OVERSAMPLE_FACTOR

Default factor by which more results are requested over the sample set.

See Also:

getOversampleFactor(), Constant Field Values

DEFAULT_SAMPLE_RATIO

public static final double DEFAULT_SAMPLE_RATIO

Default ratio between size of sample to original size of document set.

See Also:

Sampler.getSampleSet(org.apache.lucene.facet.search.ScoredDocIDs), Constant Field Values

DEFAULT_MAX_SAMPLE_SIZE

public static final int DEFAULT_MAX_SAMPLE_SIZE

Default maximum size of sample.

See Also:

Sampler.getSampleSet(org.apache.lucene.facet.search.ScoredDocIDs), Constant Field Values

DEFAULT_MIN_SAMPLE_SIZE

public static final int DEFAULT_MIN_SAMPLE_SIZE

Default minimum size of sample.

See Also:

Sampler.getSampleSet(org.apache.lucene.facet.search.ScoredDocIDs), Constant Field Values

DEFAULT_SAMPLING_THRESHOLD

public static final int DEFAULT_SAMPLING_THRESHOLD

Default sampling threshold, if number of results is less than this number - no sampling will take place

See Also:

getSampleRatio(), Constant Field Values

Constructor Detail

SamplingParams

public SamplingParams()

Method Detail

getMaxSampleSize

public final int getMaxSampleSize()

Return the maxSampleSize. In no case should the resulting sample size exceed this value.

See Also:

Sampler.getSampleSet(org.apache.lucene.facet.search.ScoredDocIDs)

getMinSampleSize

public final int getMinSampleSize()

Return the minSampleSize. In no case should the resulting sample size be smaller than this value.

See Also:

Sampler.getSampleSet(org.apache.lucene.facet.search.ScoredDocIDs)

getSampleRatio

public final double getSampleRatio()

Returns:

the sampleRatio

See Also:

Sampler.getSampleSet(org.apache.lucene.facet.search.ScoredDocIDs)

getSamplingThreshold

public final int getSamplingThreshold()

Return the samplingThreshold. Sampling would be performed only for document sets larger than this.

setMaxSampleSize

public void setMaxSampleSize(int maxSampleSize)

Parameters:

maxSampleSize - the maxSampleSize to set

See Also:

getMaxSampleSize()

setMinSampleSize

public void setMinSampleSize(int minSampleSize)

Parameters:

minSampleSize - the minSampleSize to set

See Also:

getMinSampleSize()

setSampleRatio

public void setSampleRatio(double sampleRatio)

Parameters:

sampleRatio - the sampleRatio to set

See Also:

getSampleRatio()

setSampingThreshold

public void setSampingThreshold(int sampingThreshold)

Set a sampling-threshold

See Also:

getSamplingThreshold()

validate

public boolean validate()

Check validity of sampling settings, making sure that

• minSampleSize <= maxSampleSize <= samplingThreshold
• 0 < samplingRatio <= 1

Returns:

true if valid, false otherwise

getOversampleFactor

public final double getOversampleFactor()

Return the oversampleFactor. When sampling, we would collect that much more results, so that later, when selecting top out of these, chances are higher to get actual best results. Note that having this value larger than 1 only makes sense when using a SampleFixer which finds accurate results, such as TakmiSampleFixer. When this value is smaller than 1, it is ignored and no oversampling takes place.

setOversampleFactor

public void setOversampleFactor(double oversampleFactor)

Parameters:

oversampleFactor - the oversampleFactor to set

See Also:

getOversampleFactor()