cts:value-tuples( $range-indexes as cts:reference*, [$options as xs:string*], [$query as cts:query?], [$quality-weight as xs:double?], [$forest-ids as xs:unsignedLong*] ) as json:array*
Returns value co-occurrence tuples (that is, tuples of values, each of
which appear in the same fragment) from the specified value lexicons. The
values are returned as json:array values
, where each slot contains
one of the co-occurring values. You can use
cts:frequency
on each item returned to find how many times
the tuple occurs.
Value lexicons are implemented using range indexes; consequently
this function requires a range index for each lexicon specified
in the function, and the range index must have range value positions
set to true. If there is not a range index configured for each
of the specified elements, an exception is thrown.
Parameters | |
---|---|
range-indexes | A sequence of references to range indexes. |
options |
Options. The default is ().
Options include:
|
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 (). |
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 "lazy" if "item-order" is specified, and "eager" if "frequency-order" is specified.
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 "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 tuples 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 values. A fragment
matched by query might contain multiple occurrences or no occurrences.
The number of fragments skipped does not correspond to the number of
tuples. Also, the skip is applied to the relevance ordered query matches,
not to the ordered tuples 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.
cts:value-tuples( (cts:uri-reference(), cts:element-reference(xs:QName("hello"))) ) (: Returns zero or more json:arrays listing co-occurrences between URIs with values from the lexicon for the element "hello". Requires a URI lexicon and an element range index on "hello". :)