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| <h1 id="Lucene_Net_Queries_Function_ValueSources" data-uid="Lucene.Net.Queries.Function.ValueSources" class="text-break">Namespace Lucene.Net.Queries.Function.ValueSources |
| </h1> |
| <div class="markdown level0 summary"><!-- |
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| <p>A variety of functions to use with FunctionQuery.</p> |
| </div> |
| <div class="markdown level0 conceptual"></div> |
| <div class="markdown level0 remarks"></div> |
| <h3 id="classes">Classes |
| </h3> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.BoolFunction.html">BoolFunction</a></h4> |
| <section><p>Abstract parent class for those <a class="xref" href="Lucene.Net.Queries.Function.ValueSource.html">ValueSource</a> implementations which |
| apply boolean logic to their values</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.ByteFieldSource.html">ByteFieldSource</a></h4> |
| <section><p>Obtains <span class="xref">System.Int32</span> field values from the <a class="xref" href="https://lucenenet.apache.org/docs/4.8.0-beta00013/api/core/Lucene.Net.Search.FieldCache.html">FieldCache</a> |
| using <a class="xref" href="https://lucenenet.apache.org/docs/4.8.0-beta00013/api/core/Lucene.Net.Search.IFieldCache.html#Lucene_Net_Search_IFieldCache_GetInt32s_Lucene_Net_Index_AtomicReader_System_String_Lucene_Net_Search_FieldCache_IInt32Parser_System_Boolean_">GetInt32s(AtomicReader, String, FieldCache.IInt32Parser, Boolean)</a> |
| and makes those values available as other numeric types, casting as needed. *</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.BytesRefFieldSource.html">BytesRefFieldSource</a></h4> |
| <section><p>An implementation for retrieving <a class="xref" href="Lucene.Net.Queries.Function.FunctionValues.html">FunctionValues</a> instances for <span class="xref">System.String</span> based fields.</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.ConstNumberSource.html">ConstNumberSource</a></h4> |
| <section><p><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.ConstNumberSource.html">ConstNumberSource</a> is the base class for all constant numbers</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.ConstValueSource.html">ConstValueSource</a></h4> |
| <section><p><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.ConstValueSource.html">ConstValueSource</a> returns a constant for all documents</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.DefFunction.html">DefFunction</a></h4> |
| <section><p><a class="xref" href="Lucene.Net.Queries.Function.ValueSource.html">ValueSource</a> implementation which only returns the values from the provided |
| <a class="xref" href="Lucene.Net.Queries.Function.ValueSource.html">ValueSource</a>s which are available for a particular docId. Consequently, when combined |
| with a <a class="xref" href="Lucene.Net.Queries.Function.ValueSources.ConstValueSource.html">ConstValueSource</a>, this function serves as a way to return a default |
| value when the values for a field are unavailable.</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.DivSingleFunction.html">DivSingleFunction</a></h4> |
| <section><p>Function to divide "a" by "b" |
| <p> |
| NOTE: This was DivFloatFunction in Lucene</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.DocFreqValueSource.html">DocFreqValueSource</a></h4> |
| <section><p><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.DocFreqValueSource.html">DocFreqValueSource</a> returns the number of documents containing the term.</p> |
| <div class="lucene-block lucene-internal">This is a Lucene.NET INTERNAL API, use at your own risk</div></section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.DoubleConstValueSource.html">DoubleConstValueSource</a></h4> |
| <section><p>Function that returns a constant double value for every document.</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.DoubleFieldSource.html">DoubleFieldSource</a></h4> |
| <section><p>Obtains <span class="xref">System.Double</span> field values from <a class="xref" href="https://lucenenet.apache.org/docs/4.8.0-beta00013/api/core/Lucene.Net.Search.IFieldCache.html#Lucene_Net_Search_IFieldCache_GetDoubles_Lucene_Net_Index_AtomicReader_System_String_Lucene_Net_Search_FieldCache_IDoubleParser_System_Boolean_">GetDoubles(AtomicReader, String, FieldCache.IDoubleParser, Boolean)</a> and makes |
| those values available as other numeric types, casting as needed.</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.DualSingleFunction.html">DualSingleFunction</a></h4> |
| <section><p>Abstract <a class="xref" href="Lucene.Net.Queries.Function.ValueSource.html">ValueSource</a> implementation which wraps two <a class="xref" href="Lucene.Net.Queries.Function.ValueSource.html">ValueSource</a>s |
| and applies an extendible <span class="xref">System.Single</span> function to their values. |
| <p> |
| NOTE: This was DualFloatFunction in Lucene</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.EnumFieldSource.html">EnumFieldSource</a></h4> |
| <section><p>Obtains <span class="xref">System.Int32</span> field values from <a class="xref" href="https://lucenenet.apache.org/docs/4.8.0-beta00013/api/core/Lucene.Net.Search.IFieldCache.html#Lucene_Net_Search_IFieldCache_GetInt32s_Lucene_Net_Index_AtomicReader_System_String_Lucene_Net_Search_FieldCache_IInt32Parser_System_Boolean_">GetInt32s(AtomicReader, String, FieldCache.IInt32Parser, Boolean)</a> and makes |
| those values available as other numeric types, casting as needed. |
| StrVal of the value is not the <span class="xref">System.Int32</span> value, but its <span class="xref">System.String</span> (displayed) value</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.FieldCacheSource.html">FieldCacheSource</a></h4> |
| <section><p>A base class for <a class="xref" href="Lucene.Net.Queries.Function.ValueSource.html">ValueSource</a> implementations that retrieve values for |
| a single field from the <a class="xref" href="https://lucenenet.apache.org/docs/4.8.0-beta00013/api/core/Lucene.Net.Search.FieldCache.html">FieldCache</a>.</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.IDFValueSource.html">IDFValueSource</a></h4> |
| <section><p>Function that returns <a class="xref" href="https://lucenenet.apache.org/docs/4.8.0-beta00013/api/core/Lucene.Net.Search.Similarities.TFIDFSimilarity.html#Lucene_Net_Search_Similarities_TFIDFSimilarity_Idf_System_Int64_System_Int64_">Idf(Int64, Int64)</a> |
| for every document. |
| <p> |
| Note that the configured Similarity for the field must be |
| a subclass of <span class="xref">Lucene.Net.Search.Similarities.TFIDFSimilarity</span></p> |
| <div class="lucene-block lucene-internal">This is a Lucene.NET INTERNAL API, use at your own risk</div><p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.IfFunction.html">IfFunction</a></h4> |
| <section><p>Depending on the <span class="xref">System.Boolean</span> value of the <span class="xref">Lucene.Net.Queries.Function.ValueSources.IfFunction.ifSource</span> function, |
| returns the value of the <span class="xref">Lucene.Net.Queries.Function.ValueSources.IfFunction.trueSource</span> or <span class="xref">Lucene.Net.Queries.Function.ValueSources.IfFunction.falseSource</span> function.</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.Int16FieldSource.html">Int16FieldSource</a></h4> |
| <section><p>Obtains <span class="xref">System.Int16</span> field values from the <a class="xref" href="https://lucenenet.apache.org/docs/4.8.0-beta00013/api/core/Lucene.Net.Search.FieldCache.html">FieldCache</a> |
| using <a class="xref" href="https://lucenenet.apache.org/docs/4.8.0-beta00013/api/core/Lucene.Net.Search.IFieldCache.html#Lucene_Net_Search_IFieldCache_GetInt16s_Lucene_Net_Index_AtomicReader_System_String_Lucene_Net_Search_FieldCache_IInt16Parser_System_Boolean_">GetInt16s(AtomicReader, String, FieldCache.IInt16Parser, Boolean)</a> |
| and makes those values available as other numeric types, casting as needed. |
| <p> |
| NOTE: This was ShortFieldSource in Lucene</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.Int32FieldSource.html">Int32FieldSource</a></h4> |
| <section><p>Obtains <span class="xref">System.Int32</span> field values from <a class="xref" href="https://lucenenet.apache.org/docs/4.8.0-beta00013/api/core/Lucene.Net.Search.IFieldCache.html#Lucene_Net_Search_IFieldCache_GetInt32s_Lucene_Net_Index_AtomicReader_System_String_Lucene_Net_Search_FieldCache_IInt32Parser_System_Boolean_">GetInt32s(AtomicReader, String, FieldCache.IInt32Parser, Boolean)</a> and makes those |
| values available as other numeric types, casting as needed. |
| <p> |
| NOTE: This was IntFieldSource in Lucene</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.Int64FieldSource.html">Int64FieldSource</a></h4> |
| <section><p>Obtains <span class="xref">System.Int64</span> field values from <a class="xref" href="https://lucenenet.apache.org/docs/4.8.0-beta00013/api/core/Lucene.Net.Search.IFieldCache.html#Lucene_Net_Search_IFieldCache_GetInt64s_Lucene_Net_Index_AtomicReader_System_String_Lucene_Net_Search_FieldCache_IInt64Parser_System_Boolean_">GetInt64s(AtomicReader, String, FieldCache.IInt64Parser, Boolean)</a> and makes those |
| values available as other numeric types, casting as needed. |
| <p> |
| NOTE: This was LongFieldSource in Lucene</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.JoinDocFreqValueSource.html">JoinDocFreqValueSource</a></h4> |
| <section><p>Use a field value and find the Document Frequency within another field.</p> |
| <p>@since solr 4.0</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.LinearSingleFunction.html">LinearSingleFunction</a></h4> |
| <section><p><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.LinearSingleFunction.html">LinearSingleFunction</a> implements a linear function over |
| another <a class="xref" href="Lucene.Net.Queries.Function.ValueSource.html">ValueSource</a>. |
| <p> |
| Normally Used as an argument to a <a class="xref" href="Lucene.Net.Queries.Function.FunctionQuery.html">FunctionQuery</a> |
| <p> |
| NOTE: This was LinearFloatFunction in Lucene</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.LiteralValueSource.html">LiteralValueSource</a></h4> |
| <section><p>Pass a the field value through as a <span class="xref">System.String</span>, no matter the type // Q: doesn't this mean it's a "str"?</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.MaxDocValueSource.html">MaxDocValueSource</a></h4> |
| <section><p>Returns the value of <a class="xref" href="https://lucenenet.apache.org/docs/4.8.0-beta00013/api/core/Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_MaxDoc">MaxDoc</a> |
| for every document. This is the number of documents |
| including deletions.</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.MaxSingleFunction.html">MaxSingleFunction</a></h4> |
| <section><p><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.MaxSingleFunction.html">MaxSingleFunction</a> returns the max of it's components. |
| <p> |
| NOTE: This was MaxFloatFunction in Lucene</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.MinSingleFunction.html">MinSingleFunction</a></h4> |
| <section><p><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.MinSingleFunction.html">MinSingleFunction</a> returns the min of it's components. |
| <p> |
| NOTE: This was MinFloatFunction in Lucene</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.MultiBoolFunction.html">MultiBoolFunction</a></h4> |
| <section><p>Abstract <a class="xref" href="Lucene.Net.Queries.Function.ValueSource.html">ValueSource</a> implementation which wraps multiple <a class="xref" href="Lucene.Net.Queries.Function.ValueSource.html">ValueSource</a>s |
| and applies an extendible <span class="xref">System.Boolean</span> function to their values.</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.MultiFunction.html">MultiFunction</a></h4> |
| <section><p>Abstract parent class for <a class="xref" href="Lucene.Net.Queries.Function.ValueSource.html">ValueSource</a> implementations that wrap multiple |
| <a class="xref" href="Lucene.Net.Queries.Function.ValueSource.html">ValueSource</a>s and apply their own logic.</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.MultiFunction.Values.html">MultiFunction.Values</a></h4> |
| <section></section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.MultiSingleFunction.html">MultiSingleFunction</a></h4> |
| <section><p>Abstract <a class="xref" href="Lucene.Net.Queries.Function.ValueSource.html">ValueSource</a> implementation which wraps multiple <a class="xref" href="Lucene.Net.Queries.Function.ValueSource.html">ValueSource</a>s |
| and applies an extendible <span class="xref">System.Single</span> function to their values. |
| <p> |
| NOTE: This was MultiFloatFunction in Lucene</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.MultiValueSource.html">MultiValueSource</a></h4> |
| <section><p>A <a class="xref" href="Lucene.Net.Queries.Function.ValueSource.html">ValueSource</a> that abstractly represents <a class="xref" href="Lucene.Net.Queries.Function.ValueSource.html">ValueSource</a>s for |
| poly fields, and other things.</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.NormValueSource.html">NormValueSource</a></h4> |
| <section><p>Function that returns <a class="xref" href="https://lucenenet.apache.org/docs/4.8.0-beta00013/api/core/Lucene.Net.Search.Similarities.TFIDFSimilarity.html#Lucene_Net_Search_Similarities_TFIDFSimilarity_DecodeNormValue_System_Int64_">DecodeNormValue(Int64)</a> |
| for every document. |
| <p> |
| Note that the configured Similarity for the field must be |
| a subclass of <span class="xref">Lucene.Net.Search.Similarities.TFIDFSimilarity</span></p> |
| <div class="lucene-block lucene-internal">This is a Lucene.NET INTERNAL API, use at your own risk</div><p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.NumDocsValueSource.html">NumDocsValueSource</a></h4> |
| <section><p>Returns the value of <a class="xref" href="https://lucenenet.apache.org/docs/4.8.0-beta00013/api/core/Lucene.Net.Index.IndexReader.html#Lucene_Net_Index_IndexReader_NumDocs">NumDocs</a> |
| for every document. This is the number of documents |
| excluding deletions.</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.OrdFieldSource.html">OrdFieldSource</a></h4> |
| <section><p>Obtains the ordinal of the field value from the default Lucene <a class="xref" href="https://lucenenet.apache.org/docs/4.8.0-beta00013/api/core/Lucene.Net.Search.FieldCache.html">FieldCache</a> using StringIndex. |
| <p> |
| The native lucene index order is used to assign an ordinal value for each field value. |
| <p> |
| Field values (terms) are lexicographically ordered by unicode value, and numbered starting at 1. |
| <p> |
| Example:</p> |
| <pre><code> If there were only three field values: "apple","banana","pear" |
| then ord("apple")=1, ord("banana")=2, ord("pear")=3</code></pre> |
| <p><p> |
| WARNING: Ord depends on the position in an index and can thus change when other documents are inserted or deleted, |
| or if a MultiSearcher is used. |
| <p> |
| WARNING: as of Solr 1.4, ord() and rord() can cause excess memory use since they must use a FieldCache entry |
| at the top level reader, while sorting and function queries now use entries at the segment level. Hence sorting |
| or using a different function query, in addition to ord()/rord() will double memory use.</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.PowSingleFunction.html">PowSingleFunction</a></h4> |
| <section><p>Function to raise the base "a" to the power "b" |
| <p> |
| NOTE: This was PowFloatFunction in Lucene</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.ProductSingleFunction.html">ProductSingleFunction</a></h4> |
| <section><p><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.ProductSingleFunction.html">ProductSingleFunction</a> returns the product of it's components. |
| <p> |
| NOTE: This was ProductFloatFunction in Lucene</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.QueryValueSource.html">QueryValueSource</a></h4> |
| <section><p><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.QueryValueSource.html">QueryValueSource</a> returns the relevance score of the query</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.RangeMapSingleFunction.html">RangeMapSingleFunction</a></h4> |
| <section><p><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.RangeMapSingleFunction.html">RangeMapSingleFunction</a> implements a map function over |
| another <a class="xref" href="Lucene.Net.Queries.Function.ValueSource.html">ValueSource</a> whose values fall within <code>min</code> and <code>max</code> inclusive to <code>target</code>. |
| <p> |
| Normally used as an argument to a <a class="xref" href="Lucene.Net.Queries.Function.FunctionQuery.html">FunctionQuery</a> |
| <p> |
| NOTE: This was RangeMapFloatFunction in Lucene</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.ReciprocalSingleFunction.html">ReciprocalSingleFunction</a></h4> |
| <section><p><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.ReciprocalSingleFunction.html">ReciprocalSingleFunction</a> implements a reciprocal function <code>f(x) = a/(mx+b)</code>, based on |
| the <span class="xref">System.Single</span> value of a field or function as exported by <a class="xref" href="Lucene.Net.Queries.Function.ValueSource.html">ValueSource</a>. |
| <p> |
| When a and b are equal, and <code>x>=0</code>, this function has a maximum value of 1 that drops as x increases. |
| Increasing the value of a and b together results in a movement of the entire function to a flatter part of the curve. |
| <p>These properties make this an idea function for boosting more recent documents. |
| <p>Example:<code> recip(ms(NOW,mydatefield),3.16e-11,1,1)</code> |
| <p>A multiplier of 3.16e-11 changes the units from milliseconds to years (since there are about 3.16e10 milliseconds |
| per year). Thus, a very recent date will yield a value close to 1/(0+1) or 1, |
| a date a year in the past will get a multiplier of about 1/(1+1) or 1/2, |
| and date two years old will yield 1/(2+1) or 1/3. |
| <p> |
| NOTE: This was ReciprocalFloatFunction in Lucene</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.ReverseOrdFieldSource.html">ReverseOrdFieldSource</a></h4> |
| <section><p>Obtains the ordinal of the field value from the default Lucene <a class="xref" href="https://lucenenet.apache.org/docs/4.8.0-beta00013/api/core/Lucene.Net.Search.FieldCache.html">FieldCache</a> using <a class="xref" href="https://lucenenet.apache.org/docs/4.8.0-beta00013/api/core/Lucene.Net.Search.IFieldCache.html#Lucene_Net_Search_IFieldCache_GetTermsIndex_Lucene_Net_Index_AtomicReader_System_String_System_Single_">GetTermsIndex(AtomicReader, String, Single)</a> |
| and reverses the order. |
| <p> |
| The native lucene index order is used to assign an ordinal value for each field value. |
| <p>Field values (terms) are lexicographically ordered by unicode value, and numbered starting at 1. |
| <p> |
| Example of reverse ordinal (rord):</p> |
| <pre><code> If there were only three field values: "apple","banana","pear" |
| then rord("apple")=3, rord("banana")=2, ord("pear")=1</code></pre> |
| <p><p> |
| WARNING: Ord depends on the position in an index and can thus change when other documents are inserted or deleted, |
| or if a MultiSearcher is used. |
| <p> |
| WARNING: as of Solr 1.4, ord() and rord() can cause excess memory use since they must use a FieldCache entry |
| at the top level reader, while sorting and function queries now use entries at the segment level. Hence sorting |
| or using a different function query, in addition to ord()/rord() will double memory use.</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.ScaleSingleFunction.html">ScaleSingleFunction</a></h4> |
| <section><p>Scales values to be between <code>min</code> and <code>max</code>. |
| <p>This implementation currently traverses all of the source values to obtain |
| their min and max. |
| <p>This implementation currently cannot distinguish when documents have been |
| deleted or documents that have no value, and 0.0 values will be used for |
| these cases. This means that if values are normally all greater than 0.0, one can |
| still end up with 0.0 as the min value to map from. In these cases, an |
| appropriate map() function could be used as a workaround to change 0.0 |
| to a value in the real range. |
| <p> |
| NOTE: This was ScaleFloatFunction in Lucene</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.SimpleBoolFunction.html">SimpleBoolFunction</a></h4> |
| <section><p><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.BoolFunction.html">BoolFunction</a> implementation which applies an extendible <span class="xref">System.Boolean</span> |
| function to the values of a single wrapped <a class="xref" href="Lucene.Net.Queries.Function.ValueSource.html">ValueSource</a>.</p> |
| <p>Functions this can be used for include whether a field has a value or not, |
| or inverting the <span class="xref">System.Boolean</span> value of the wrapped <a class="xref" href="Lucene.Net.Queries.Function.ValueSource.html">ValueSource</a>.</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.SimpleSingleFunction.html">SimpleSingleFunction</a></h4> |
| <section><p>A simple <span class="xref">System.Single</span> function with a single argument |
| <p> |
| NOTE: This was SimpleFloatFunction in Lucene</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.SingleFieldSource.html">SingleFieldSource</a></h4> |
| <section><p>Obtains <span class="xref">System.Single</span> field values from <a class="xref" href="https://lucenenet.apache.org/docs/4.8.0-beta00013/api/core/Lucene.Net.Search.IFieldCache.html#Lucene_Net_Search_IFieldCache_GetSingles_Lucene_Net_Index_AtomicReader_System_String_Lucene_Net_Search_FieldCache_ISingleParser_System_Boolean_">GetSingles(AtomicReader, String, FieldCache.ISingleParser, Boolean)</a> and makes those |
| values available as other numeric types, casting as needed. |
| <p> |
| NOTE: This was FloatFieldSource in Lucene</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.SingularFunction.html">SingularFunction</a></h4> |
| <section><p>A function with a single (one) argument. |
| <p> |
| NOTE: This was SingleFunction in Lucene, changed to avoid conusion with operations on the datatype <span class="xref">System.Single</span>.</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.SumSingleFunction.html">SumSingleFunction</a></h4> |
| <section><p><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.SumSingleFunction.html">SumSingleFunction</a> returns the sum of its components. |
| <p> |
| NOTE: This was SumFloatFunction in Lucene</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.SumTotalTermFreqValueSource.html">SumTotalTermFreqValueSource</a></h4> |
| <section><p><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.SumTotalTermFreqValueSource.html">SumTotalTermFreqValueSource</a> returns the number of tokens. |
| (sum of term freqs across all documents, across all terms). |
| Returns -1 if frequencies were omitted for the field, or if |
| the codec doesn't support this statistic.</p> |
| <div class="lucene-block lucene-internal">This is a Lucene.NET INTERNAL API, use at your own risk</div></section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.TermFreqValueSource.html">TermFreqValueSource</a></h4> |
| <section><p>Function that returns <span class="xref">Lucene.Net.Index.DocsEnum.Freq</span> for the |
| supplied term in every document. |
| <p> |
| If the term does not exist in the document, returns 0. |
| If frequencies are omitted, returns 1.</p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.TFValueSource.html">TFValueSource</a></h4> |
| <section><p>Function that returns <a class="xref" href="https://lucenenet.apache.org/docs/4.8.0-beta00013/api/core/Lucene.Net.Search.Similarities.TFIDFSimilarity.html#Lucene_Net_Search_Similarities_TFIDFSimilarity_Tf_System_Single_">Tf(Single)</a> |
| for every document. |
| <p> |
| Note that the configured Similarity for the field must be |
| a subclass of <span class="xref">Lucene.Net.Search.Similarities.TFIDFSimilarity</span></p> |
| <div class="lucene-block lucene-internal">This is a Lucene.NET INTERNAL API, use at your own risk</div><p> |
| </section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.TotalTermFreqValueSource.html">TotalTermFreqValueSource</a></h4> |
| <section><p><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.TotalTermFreqValueSource.html">TotalTermFreqValueSource</a> returns the total term freq |
| (sum of term freqs across all documents). |
| Returns -1 if frequencies were omitted for the field, or if |
| the codec doesn't support this statistic.</p> |
| <div class="lucene-block lucene-internal">This is a Lucene.NET INTERNAL API, use at your own risk</div></section> |
| <h4><a class="xref" href="Lucene.Net.Queries.Function.ValueSources.VectorValueSource.html">VectorValueSource</a></h4> |
| <section><p>Converts individual <a class="xref" href="Lucene.Net.Queries.Function.ValueSource.html">ValueSource</a> instances to leverage the FunctionValues *Val functions that work with multiple values, |
| i.e. <a class="xref" href="Lucene.Net.Queries.Function.FunctionValues.html#Lucene_Net_Queries_Function_FunctionValues_DoubleVal_System_Int32_System_Double___">DoubleVal(Int32, Double[])</a></p> |
| </section> |
| </article> |
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