MarkLogic 9 Product Documentation
cts:value-co-occurrences

cts:value-co-occurrences(
   $range-index-1 as cts:reference,
   $range-index-2 as cts:reference,
   [$options as xs:string*],
   [$query as cts:query?],
   [$quality-weight as xs:double?],
   [$forest-ids as xs:unsignedLong*]
) as element(cts:co-occurrence)*

Summary

Returns value co-occurrences (that is, pairs of values, both of which appear in the same fragment) from the specified value lexicon(s). The values are returned as an XML element with two children, each child containing one of the co-occurring values. You can use cts:frequency on each item returned to find how many times the pair occurs. Value lexicons are implemented using range indexes; consequently this function requires a range index for each input index reference. If an index or lexicon is not configured for any of the input references, an exception is thrown.

Parameters
range-index-1	A reference to a range index.
range-index-2	A reference to a range index.
options	Options. The default is (). Options include: "ascending" Co-occurrences should be returned in ascending order. "descending" Co-occurrences should be returned in descending order. "any" Co-occurrences from any fragment should be included. "document" Co-occurrences from document fragments should be included. "properties" Co-occurrences from properties fragments should be included. "locks" Co-occurrences from locks fragments should be included. "frequency-order" Co-occurrences should be returned ordered by frequency. "item-order" Co-occurrences should be returned ordered by item. "fragment-frequency" Frequency should be the number of fragments with an included co-occurrences. This option is used with `cts:frequency`. "item-frequency" Frequency should be the number of occurences of an included co-occurrence. This option is used with `cts:frequency`. "timezone=TZ" Return timezone sensitive values (dateTime, time, date, gYearMonth, gYear, gMonth, and gDay) adjusted to the timezone specified by TZ. Example timezones: Z, -08:00, +01:00. "ordered" Include co-occurrences only when the value from the first lexicon appears before the value from the second lexicon. Requires that word positions be enabled for both lexicons. "proximity=N" Include co-occurrences only when the values appear within N words of each other. Requires that word positions be enabled for both lexicons. "limit=N" Return no more than N co-occurrences. You should not use this option with the "skip" option. Use "truncate" instead. "skip=N" Skip over fragments selected by the `cts:query` to treat the Nth fragment as the first fragment. Co-occurrences from skipped fragments are not included. This option affects the number of fragments selected by the `cts:query` to calculate frequencies. Only applies when a `$query` parameter is specified. "sample=N" Return only co-occurrences from the first N fragments after skip selected by the `cts:query`. This option does not affect the number of fragments selected by the `cts:query` to calculate frequencies. Only applies when a `$query` parameter is specified. Return only co-occurrences from the first N fragments after skip selected by the `cts:query`, bit do not affect frequencies. Only applies when a `$query` parameter is specified. "truncate=N" Include only co-occurrences from the first N fragments after skip selected by the `cts:query`. This option also affects the number of fragments selected by the `cts:query` to calculate frequencies. Only applies when a `$query` parameter is specified. "score-logtfidf" Compute scores using the logtfidf method. Only applies when a `$query` parameter is specified. "score-logtf" Compute scores using the logtf method. Only applies when a `$query` parameter is specified. "score-simple" Compute scores using the simple method. Only applies when a `$query` parameter is specified. "score-random" Compute scores using the random method. Only applies when a `$query` parameter is specified. "score-zero" Compute all scores as zero. Only applies when a `$query` parameter is specified. "checked" Word positions should be checked when resolving the query. "unchecked" Word positions should not be checked when resolving the query. "too-many-positions-error" If too much memory is needed to perform positions calculations to check whether a document matches a query, return an XDMP-TOOMANYPOSITIONS error, instead of accepting the document as a match. "eager" Perform most of the work concurrently before returning the first item from the indexes, and only some of the work sequentially while iterating through the rest of the items. This usually takes the shortest time for a complete item-order result or for any frequency-order result. "lazy" Perform only some the work concurrently before returning the first item from the indexes, and most of the work sequentially while iterating through the rest of the items. This usually takes the shortest time for a small item-order partial result. "concurrent" Perform the work concurrently in another thread. This is a hint to the query optimizer to help parallelize the lexicon work, allowing the calling query to continue performing other work while the lexicon processing occurs. This is especially useful in cases where multiple lexicon calls occur in the same query (for example, resolving many facets in a single query). "map" Return results as a single map:map value instead of as an element(cts:co-occurrence)* sequence .
query	Only include co-occurrences in fragments selected by the `cts:query`, and compute frequencies from this set of included co-occurrences. The co-occurrences do not need to match the query, but they must occur in fragments selected by the query. The fragments are not filtered to ensure they match the query, but instead selected in the same manner as "unfiltered" `cts:search` operations. If a string is entered, the string is treated as a `cts:word-query` of the specified string.
quality-weight	A document quality weight to use when computing scores. The default is 1.0.
forest-ids	A sequence of IDs of forests to which the search will be constrained. An empty sequence means to search all forests in the database. The default is ().

Usage Notes

Only one of "frequency-order" or "item-order" may be specified in the options parameter. If neither "frequency-order" nor "item-order" is specified, then the default is "item-order".

Only one of "fragment-frequency" or "item-frequency" may be specified in the options parameter. If neither "fragment-frequency" nor "item-frequency" is specified, then the default is "fragment-frequency".

Only one of "ascending" or "descending" may be specified in the options parameter. If neither "ascending" nor "descending" is specified, then the default is "ascending" if "item-order" is specified, and "descending" if "frequency-order" is specified.

Only one of "eager" or "lazy" may be specified in the options parameter. If neither "eager" nor "lazy" is specified, then the default is "eager" if "frequency-order" or "map" is specified, otherwise "lazy".

Only one of "any", "document", "properties", or "locks" may be specified in the options parameter. If none of "any", "document", "properties", or "locks" are specified and there is a $query parameter, then the default is "document". If there is no $query parameter then the default is "any".

Only one of the "score-logtfidf", "score-logtf", "score-simple", "score-random", or "score-zero" options may be specified in the options parameter. If none of "score-logtfidf", "score-logtf", "score-simple", "score-random", or "score-zero" are specified, then the default is "score-logtfidf".

Only one of the "checked" or "unchecked" options may be specified in the options parameter. If neither "checked" nor "unchecked" are specified, then the default is "checked".

If "collation=URI" is not specified in the options parameter, then the default collation is used. If a lexicon with that collation does not exist, an error is thrown.

If "sample=N" is not specified in the options parameter, then all included co-occurrences may be returned. If a $query parameter is not present, then "sample=N" has no effect.

If "truncate=N" is not specified in the options parameter, then co-occurrences from all fragments selected by the $query parameter are included. If a $query parameter is not present, then "truncate=N" has no effect.

To incrementally fetch a subset of the co-occurrences returned by this function, use fn:subsequence on the output, rather than the "skip" option. The "skip" option is based on fragments matching the query parameter (if present), not on occurrences. A fragment matched by query might contain multiple occurrences or no occurrences. The number of fragments skipped does not correspond to the number of values. Also, the skip is applied to the relevance ordered query matches, not to the ordered co-occurrences list.

When using the "skip" option, use the "truncate" option rather than the "limit" option to control the number of matching fragments from which to draw values.

Example

(: Suppose we have a document with many news items in the database. :)

xdmp:document-insert("/news.xml",
<news>
  <sale>
   <sold-item>Bike</sold-item>
    <name>
      <first>John</first><last>Griffith</last>
    </name>
    <city>Reno</city>
    <text>...</text>
  </sale>
  <sale>
   <sold-item>Car</sold-item>
    <name>
      <first>Will</first><last>Shields</last>
    </name>
    <city>Lexington</city>
    <text>...</text>
  </sale>
  <theft>
    <stolen-item>Bike</stolen-item>
    <reporter>
      <first>John</first><last>Smith</last>
    </reporter>
    <city>Las Vegas</city>
    <text>...</text>
  </theft>
  <theft>
    <stolen-item>Car</stolen-item>
    <reporter>
      <first>Will</first><last>Shields</last>
    </reporter>
    <city>Indianapolis</city>
    <text>...</text>
  </theft>
</news>);


(: Now suppose we have two path range indexes defined.
     Index1: /news/sale/sold-item string type
     Index2: /news/sale/city  string type

   We can find co-occurrence of items sold and the city it was sold in.
:)

  cts:value-co-occurrences(cts:path-reference("/news/sale/sold-item"),
                           cts:path-reference("/news/sale/city"))
=>
<cts:co-occurrence xmlns:cts="http://marklogic.com/cts"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <cts:value xsi:type="xs:string">Bike</cts:value>
  <cts:value xsi:type="xs:string">Lexington</cts:value>
</cts:co-occurrence>
<cts:co-occurrence xmlns:cts="http://marklogic.com/cts"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <cts:value xsi:type="xs:string">Bike</cts:value>
  <cts:value xsi:type="xs:string">Reno</cts:value>
</cts:co-occurrence>
<cts:co-occurrence xmlns:cts="http://marklogic.com/cts"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <cts:value xsi:type="xs:string">Car</cts:value>
  <cts:value xsi:type="xs:string">Lexington</cts:value>
</cts:co-occurrence>
<cts:co-occurrence xmlns:cts="http://marklogic.com/cts"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <cts:value xsi:type="xs:string">Car</cts:value>
  <cts:value xsi:type="xs:string">Reno</cts:value>
</cts:co-occurrence>

MarkLogic 9 Product Documentationcts:value-co-occurrences

Summary

Usage Notes

Example

MarkLogic 9 Product Documentation
cts:value-co-occurrences