org.elasticsearch.search.suggest.phrase

Class PhraseSuggestionBuilder.DirectCandidateGenerator

java.lang.Object

org.elasticsearch.search.suggest.phrase.PhraseSuggestionBuilder.CandidateGenerator

org.elasticsearch.search.suggest.phrase.PhraseSuggestionBuilder.DirectCandidateGenerator

All Implemented Interfaces:

ToXContent

Enclosing class:

PhraseSuggestionBuilder

public static final class PhraseSuggestionBuilder.DirectCandidateGenerator
extends PhraseSuggestionBuilder.CandidateGenerator

Nested Class Summary

Nested classes/interfaces inherited from interface org.elasticsearch.common.xcontent.ToXContent

ToXContent.DelegatingMapParams, ToXContent.MapParams, ToXContent.Params

Field Summary

Fields inherited from interface org.elasticsearch.common.xcontent.ToXContent

EMPTY_PARAMS

Constructor Summary

Constructors

Constructor and Description
DirectCandidateGenerator(String field)

Method Summary

Modifier and Type	Method and Description
PhraseSuggestionBuilder.DirectCandidateGenerator	accuracy(float accuracy) Sets how similar the suggested terms at least need to be compared to the original suggest text tokens.
PhraseSuggestionBuilder.DirectCandidateGenerator	maxEdits(Integer maxEdits) Sets the maximum edit distance candidate suggestions can have in order to be considered as a suggestion.
PhraseSuggestionBuilder.DirectCandidateGenerator	maxInspections(Integer maxInspections) A factor that is used to multiply with the size in order to inspect more candidate suggestions.
PhraseSuggestionBuilder.DirectCandidateGenerator	maxTermFreq(float maxTermFreq) Sets a maximum threshold in number of documents a suggest text token can exist in order to be corrected.
PhraseSuggestionBuilder.DirectCandidateGenerator	minDocFreq(float minDocFreq) Sets a minimal threshold in number of documents a suggested term should appear in.
PhraseSuggestionBuilder.DirectCandidateGenerator	minWordLength(int minWordLength) The minimum length a suggest text term must have in order to be corrected.
PhraseSuggestionBuilder.DirectCandidateGenerator	postFilter(String postFilter) Sets a filter (analyzer) that is applied to each of the generated tokens before they are passed to the actual phrase scorer.
PhraseSuggestionBuilder.DirectCandidateGenerator	preFilter(String preFilter) Sets a filter (analyzer) that is applied to each of the tokens passed to this candidate generator.
PhraseSuggestionBuilder.DirectCandidateGenerator	prefixLength(int prefixLength) Sets the number of minimal prefix characters that must match in order be a candidate suggestion.
PhraseSuggestionBuilder.DirectCandidateGenerator	size(int size) Sets the maximum suggestions to be returned per suggest text term.
PhraseSuggestionBuilder.DirectCandidateGenerator	sort(String sort) Sets how to sort the suggest terms per suggest text token.
PhraseSuggestionBuilder.DirectCandidateGenerator	stringDistance(String stringDistance) Sets what string distance implementation to use for comparing how similar suggested terms are.
PhraseSuggestionBuilder.DirectCandidateGenerator	suggestMode(String suggestMode) The global suggest mode controls what suggested terms are included or controls for what suggest text tokens, terms should be suggested for.
XContentBuilder	toXContent(XContentBuilder builder, ToXContent.Params params)

Methods inherited from class org.elasticsearch.search.suggest.phrase.PhraseSuggestionBuilder.CandidateGenerator

getType

Methods inherited from class java.lang.Object

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

Constructor Detail

DirectCandidateGenerator

public DirectCandidateGenerator(String field)

Parameters:

field - Sets from what field to fetch the candidate suggestions from.

Method Detail

suggestMode

public PhraseSuggestionBuilder.DirectCandidateGenerator suggestMode(String suggestMode)

The global suggest mode controls what suggested terms are included or controls for what suggest text tokens, terms should be suggested for. Three possible values can be specified:

1. missing - Only suggest terms in the suggest text that aren't in the index. This is the default.
2. popular - Only suggest terms that occur in more docs then the original suggest text term.
3. always - Suggest any matching suggest terms based on tokens in the suggest text.

accuracy

public PhraseSuggestionBuilder.DirectCandidateGenerator accuracy(float accuracy)

Sets how similar the suggested terms at least need to be compared to the original suggest text tokens. A value between 0 and 1 can be specified. This value will be compared to the string distance result of each candidate spelling correction.

Default is 0.5

size

public PhraseSuggestionBuilder.DirectCandidateGenerator size(int size)

Sets the maximum suggestions to be returned per suggest text term.

sort

public PhraseSuggestionBuilder.DirectCandidateGenerator sort(String sort)

Sets how to sort the suggest terms per suggest text token. Two possible values:

1. score - Sort should first be based on score, then document frequency and then the term itself.
2. frequency - Sort should first be based on document frequency, then scotr and then the term itself.

What the score is depends on the suggester being used.

stringDistance

public PhraseSuggestionBuilder.DirectCandidateGenerator stringDistance(String stringDistance)

Sets what string distance implementation to use for comparing how similar suggested terms are. Four possible values can be specified:

1. internal - This is the default and is based on damerau_levenshtein, but highly optimized for comparing string distance for terms inside the index.
2. damerau_levenshtein - String distance algorithm based on Damerau-Levenshtein algorithm.
3. levenstein - String distance algorithm based on Levenstein edit distance algorithm.
4. jarowinkler - String distance algorithm based on Jaro-Winkler algorithm.
5. ngram - String distance algorithm based on character n-grams.

maxEdits

public PhraseSuggestionBuilder.DirectCandidateGenerator maxEdits(Integer maxEdits)

Sets the maximum edit distance candidate suggestions can have in order to be considered as a suggestion. Can only be a value between 1 and 2. Any other value result in an bad request error being thrown. Defaults to 2.

maxInspections

public PhraseSuggestionBuilder.DirectCandidateGenerator maxInspections(Integer maxInspections)

A factor that is used to multiply with the size in order to inspect more candidate suggestions. Can improve accuracy at the cost of performance. Defaults to 5.

maxTermFreq

public PhraseSuggestionBuilder.DirectCandidateGenerator maxTermFreq(float maxTermFreq)

Sets a maximum threshold in number of documents a suggest text token can exist in order to be corrected. Can be a relative percentage number (e.g 0.4) or an absolute number to represent document frequencies. If an value higher than 1 is specified then fractional can not be specified. Defaults to 0.01.

This can be used to exclude high frequency terms from being suggested. High frequency terms are usually spelled correctly on top of this this also improves the suggest performance.

prefixLength

public PhraseSuggestionBuilder.DirectCandidateGenerator prefixLength(int prefixLength)

Sets the number of minimal prefix characters that must match in order be a candidate suggestion. Defaults to 1. Increasing this number improves suggest performance. Usually misspellings don't occur in the beginning of terms.

minWordLength

public PhraseSuggestionBuilder.DirectCandidateGenerator minWordLength(int minWordLength)

The minimum length a suggest text term must have in order to be corrected. Defaults to 4.

minDocFreq

public PhraseSuggestionBuilder.DirectCandidateGenerator minDocFreq(float minDocFreq)

Sets a minimal threshold in number of documents a suggested term should appear in. This can be specified as an absolute number or as a relative percentage of number of documents. This can improve quality by only suggesting high frequency terms. Defaults to 0f and is not enabled. If a value higher than 1 is specified then the number cannot be fractional.

preFilter

public PhraseSuggestionBuilder.DirectCandidateGenerator preFilter(String preFilter)

Sets a filter (analyzer) that is applied to each of the tokens passed to this candidate generator. This filter is applied to the original token before candidates are generated.

postFilter

public PhraseSuggestionBuilder.DirectCandidateGenerator postFilter(String postFilter)

Sets a filter (analyzer) that is applied to each of the generated tokens before they are passed to the actual phrase scorer.

toXContent

public XContentBuilder toXContent(XContentBuilder builder,
                                  ToXContent.Params params)
                           throws IOException

Throws:

IOException