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Following are the Siddhi extensions you can use in processing events using WSO2 CEP.

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Excerpt

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1.FORMAT FOR FUNCTIONS

functionName

<returnType r1> functionName ( < paramType> p1) (FOR ONE RETURN TYPE & ONE PARAMETER TYPE)

< returnType | returnType > functionName(<paramType|paramType> p1, <paramType|paramType> p2) (FOR ONE RETURN TYPE & MANY PARAMETER TYPES)

[< returnType | returnType > r1, < returnType | returnType > r2 ] functionName(<paramType|paramType> p1) (FOR MANY RETURN TYPES & ONE PARAMETER TYPE)

Extension Type: Function | Aggregate Function | Stream Function | Stream Processor | Window
Description:
Parameter : p1 :
Return Parameter : r1:
Example:

functionName

<returnType> functionName ( < paramType> p1)(FOR ONE RETURN TYPE & ONE PARAMETER TYPE)

<returnType|returnType> functionName(<paramType|paramType> p1, <paramType|paramType> p2)(FOR ONE RETURN TYPE & MANY PARAMETER TYPES)

[< returnType | returnType > r1, < returnType | returnType > r2 ] functionName(<paramType|paramType> p1)(FOR MANY RETURN TYPES & ONE PARAMETER TYPE)

Extension Type: Function | Aggregate Function | Stream Function | Aggregate Stream Function | Window
Description:
Parameter : p1 :
Return Parameter : r1 :
Example:

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Syntax	`<double> abs(<float\|double> p1)`
Extension Type	Function
Description	Returns the absolute value of `p1`. This function wraps the `java.lang.Math.abs()` function.
Examples	Both the following queries return 3 since the absolute value of both `3` and `-3` is `3`. `abs(3)` `abs(-3)`

acos

Syntax	`<double> acos(<float\|double> p1)`
Extension Type	Function
Description	If -1 <= p1 <= 1, this function returns the arc-cosine (inverse cosine) of `p1`. If not, it returns `NULL.` The return value is in radian scale. This function wraps the `java.lang.Math.acos()` function.
Example	`acos(0.5)` returns `1.0471975511965979`.

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Syntax	`<double> asin (<float\|double> p1)`
Extension Type	Function
Description	If -1 <= p1 <= 1, this function returns the arc-sin (inverse sine) of `p1`. If not, it returns `NULL`. The return value is in radian scale. This function wraps the `java.lang.Math.asin()` function.
Example	`asin(0.5)` returns `0.5235987755982989`.

atan

Syntax	`<double> atan(<int\|long\|float\|double> p1)`
Extension Type	Function
Description	Returns the arc-tangent (inverse tangent) of `p1`. The return value is in radian scale. This function wraps the `java.lang.Math.atan()` function.
Examples	`atan(6d)` returns `1.4056476493802699`.

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Syntax	`<double> cbrt(<int\|long\|float\|double> p1)`
Extension Type	Function
Description	Returns the cube-root of `p1` (`p1` is in radians). This function wraps the `java.lang.Math.cbrt()` function.
Example	`cbrt(17d)` returns `2.5712815906582356`.

e

Syntax	`<double> e()`
Extension Type	Function
Description	Returns the `java.lang.Math.E` constant, which is the closest double value to `e` (which is the base of the natural logarithms).
Example	`e()` returns `2.7182818284590452354`.

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Syntax	`<boolean> isInfinite(<float\|double> p1)`
Extension Type	Function
Description	This function wraps the `java.lang.Float.isInfinite()` and `java.lang.Double.isInfinite()` functions that return `true` if `p1` is infinitely large in magnitude, or return `false` otherwise.
Example	`isInfinite(java.lang.Double.POSITIVE_INFINITY)` returns `true`.

isNan

Syntax	`< boolean> isNan(<float\|double> p1)`
Extension Type	Function
Description	This function wraps the `java.lang.Float.isNaN()` and `java.lang.Double.isNaN()` functions that return `true` if `p1` is a `NaN` (Not-a-Number) value, or return false otherwise.
Example	`isNan(java.lang.Math.log(-12d)`) returns `true`.

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Syntax	`<double> pi ( )`
Extension Type	Function
Description	Returns the `java.lang.Math.PI` constant, which is the closest value to `pi` (i.e. the ratio of the circumference of a circle to its diameter).
Example	`pi()` always returns `3.141592653589793`.

power

Syntax	`<double> power ( < int\|long\|float\|double> value, <int\|long\|float\|double> toPower )`
Extension Type	Function
Description	Returns `value` raised to the power of `toPower`.
Example	`power(5.6d, 3.0d)` returns `175.61599999999996`.

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Syntax	`<double> sin (< int\|long\|float\|double > p1)`
Extension Type	Function
Description	Returns the sine of `p1` (`p1` is in radians). This function wraps the `java.lang.Math.sin()` function.
Example	`sin(6d`) returns `-0.27941549819892586.`

sinh

Syntax	`<double> sinh (< int\|long\|float\|double > p1)`
Extension Type	Function
Description	Returns the hyperbolic sine of `p1` (`p1` is in radians). This function wraps the `java.lang.Math.sinh()` function.
Example	`sinh(6d)` returns `201.71315737027922`.

sqrt

Syntax	`<double> sqrt (< int\|long\|float\|double > p1)`
Extension Type	Function
Description	Returns the square-root of `p1`. This function wraps the `java.lang.Math.sqrt()` function.
Example	`sqrt(4d)` returns `2`.

tan

Syntax	`<double> tan (< int\|long\|float\|double > p1)`
Extension Type	Function
Description	Returns the tan of `p1` (`p1` is in radians). This function wraps the `java.lang.Math.tan()` function.
Example	`tan(6d)` returns `-0.29100619138474915`.

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Syntax	`<string> charAt(<string> str, <int> index)`
Extension Type	Function
Description	Returns the char value as a string value at the specified index.
Example	`charAt("WSO2", 1)` returns `'S'`.

coalesce

Syntax	`< int\|long\|float\|double\|string\|boolean > coalesce (< int\|long\|float\|double\|string\|boolean > arg1, < int\|long\|float\|double\|string\|boolean > arg2 ,.., < int\|long\|float\|double\|string\|boolean > argN )`
Extension Type	Function
Description	Returns the value of the first of its input parameters that is not null.
Parameters	This functions accepts any number of parameters. The parameters can be of different types.
Return Type	This is the same as the type of the first input parameter that is not null.
Examples	`coalesce("123", null, "789")` returns `"123"`. `coalesce(null, "BBB", "CCC")` returns `"BBB"`. `coalesce(null, null, null)` returns `null`.

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Syntax	`<string> lower ( < string> str)`
Extension Type	Function
Description	Converts the capital letters in the `str` input string to the equivalent simple letters.
Example	`lower("WSO2 cep ")` returns `"wso2 cep "`.

regexp

Syntax	`<boolean> regexp ( < string> str, <string> regex )`
Extension Type	Function
Description	Returns `true` if the given string (i.e. `str``)` matches the given regular expression (i.e. `regex` ). Returns `false` if the string does not match the regular expression.
Example	`regexp("WSO2 abcdh", "WSO(.*h)")` returns `true`.

repeat

Syntax	`<string> repeat ( < string> str, <int> times)`
Extension Type	Function
Description	Repeats the specified string (i.e. `string`) for the specified number of times (i.e. `times`).
Example	`repeat("StRing 1", 3)` returns `"StRing 1StRing 1StRing 1"`.

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Syntax	`<string> reverse ( < string> str)`
Extension Type	Function
Description	Returns the reverse ordered string of `str`.
Example	`reverse("Hello World")` returns `"dlroW olleH"`.

strcmp

Syntax	`<int> strcmp ( < string> str, <string> compareTo)`
Extension Type	Function
Description	Compares `str` with `compareTo` strings lexicographically.
Examples	`strcmp("Hello", 'Hello')` returns `0`. `strcmp("AbCDefghiJ KLMN", 'Hello')` returns `-7`.

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Syntax	`<double, double, string> geocode (<string> location` `)`
Extension Type	StreamProcessor
Description	Transforms a location to its geo-coordinates ( `longitude` and `latitude` ) and formatted address.
Example	`geocode(duplication rd)` returns the following data with adherring latitude, longitude, and `formattedAddress` attribute names respectively. `6.8995244d, 79.8556202d, "R A De Mel Mawatha, Colombo, Sri Lanka"`

r
Anchor
R
R

First you need to setup the prerequisites.

This extension allows you to execute R scripts within Siddhi query. Following are the functions of the R extension.

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regex
Anchor
regex
regex

This extension provides basic RegEx execution capabilities to Siddhi. Following are the functions of the RegEx extension.

find

Syntax	`<bool> find (<string> regex , <string> inputSequence )`
Extension Type	Function
Description	This method attempts to find the next sub-sequence of the `inputSequence` that matches the `regex` pattern. It returns `true` if such a sub sequence exists, or returns `false` otherwise.
Examples	`find("\d\d(.)WSO2", "21 products are produced by WSO2 currently")` returns `true`. `find("\d\d(.)WSO2", "21 products are produced currently")` returns `false`.

Syntax	`<bool> find (<string> regex , <string> inputSequence, <int> startingIndex )`
Extension Type	Function
Description	This method attempts to find the next sub-sequence of the `inputSequence` that matches the `regex` pattern starting from given index (i.e. `startingIndex`). It returns `true` if such a sub sequence exists, or returns `false` otherwise.
Examples	`find("\d\d(.)WSO2", "21 products are produced within 10 years by WSO2 currently by WSO2 employees", 30)` returns `true`. `find("\d\d(.)WSO2", "21 products are produced within 10 years by WSO2 currently by WSO2 employees", 35)` returns `false`.

group

Syntax	`<string> group (<string> regex , <string> inputSequence , <int> groupId )`
Extension Type	Function
Description	Returns the input sub-sequence captured by the given group during the previous match operation. Returns `null` if no sub-sequence was found during the previous match operation. For more information about the match operation, see matches.
Example	`group("(\d\d)(.)(WSO2.)", "21 products are produced within 10 years by WSO2 currently by WSO2 employees", 3)` returns `"WSO2 employees"`.

lookingAt

Syntax	`<string> lookingAt (<string> regex , <string> inputSequence )`
Extension Type	Function
Description	This method attempts to match the `inputSequence` against the `regex` pattern starting at the beginning.
Examples	`lookingAt("\d\d(.)WSO2", "21 products are produced by WSO2 currently in Sri Lanka"`) returns `true`. `lookingAt("WSO2(.)middleware(.*)", "sample test string and WSO2 is situated in trace and its a middleware company")` returns `false`.

matches
Anchor
match
match

Syntax	`<string> matches (<string> regex , <string> inputSequence )`
Extension Type	Function
Description	This method attempts to match the entire `inputSequence` against the `regex` pattern.
Examples	`matches("WSO2(.)middleware(.)", "WSO2 is situated in trace and its a middleware company")` returns `true`. `matches("WSO2(.*)middleware", "WSO2 is situated in trace and its a middleware company")` returns `false`.

time
Anchor
time
time

This extension provides time related functionality to Siddhi such as getting current time, current date, manipulating/formatting dates, etc. Following are the functions of the time extension.

currentDate

Syntax	`<string> currentDate ( )`
Extension Type	Function
Description	Returns the current system date in the `yyyy-MM-dd` format.
Example	`currentDate()` returns `2015-08-20`.

currentTime

Syntax	`<string> currentTime ( )`
Extension Type	Function
Description	Returns the current system time in the `HH:mm:ss` format.
Example	`currentTime()` returns `13:15:10`.

currentTimestamp

Syntax	`<string> currentTimestamp ( )`
Extension Type	Function
Description	Returns the current system timestamp in the `yyyy-MM-dd HH:mm:ss` format.
Example	`currentTime()` returns `2015-08-20 13:15:10`.

dateAdd

The common parameters of this function are described below.

dateValue: A value of date. e.g., "2014-11-11 13:23:44.657", "2014-11-11", "13:23:44.657"
expr: The amount by which the selected part of the date format should be incremented. e.g., 2 ,5 ,10 etc.
unit: The part of the date format that needs to be manipulated. e.g., "MINUTE" , "HOUR" , "MONTH" , "YEAR" , "QUARTER" , * "WEEK" , "DAY" , "SECOND"
dateFormat: The date format of the date value provided. e.g., yyyy-MM-dd HH:mm:ss.SSS
timestampInMilliseconds: The date value in milliseconds (from the epoch). e.g., 1415712224000L

Syntax	`<string> dateAdd (<string> dateValue , <long> expr, <string> unit, <string> dateFormat )`
Extension Type	Function
Description	Returns the specified date and time with the selected `unit` of the specified `dateValue` incremented by the given amount (i.e. `expr`).
Example	`dateAdd("2014-11-11 13:23:44", 2, 'year',"yyyy-MM-dd HH:mm:ss")` returns `"2016-11-11 13:23:44"`.

Syntax	`<string> dateAdd (<string> dateValue , < long > expr, <string> unit )`
Extension Type	Function
Description	Returns the specified date and time with the selected `unit`of the specified `dateValue` incremented by the given amount (i.e. `expr`).
Example	`dateAdd("2014-11-11 13:23:44", 2, 'year')` returns `"2016-11-11 13:23:44"`.

Syntax	`<string> dateAdd (<long> timestampInMilliseconds, < long > expr, <string> unit )`
Extension Type	Function
Description	Returns the specified time stamp with the selected `unit`of the specified `timestampInMilliseconds` incremented by the given amount (i.e. `expr`).
Example	`dateAdd(1415692424000L, 2, 'year')` returns `"2016-11-11 13:23:44"`.

dateSub

The common parameters of this function are described below.

dateValue: A value of date. e.g., "2014-11-11 13:23:44.657", "2014-11-11", "13:23:44.657"
expr: The amount by which the selected part of the date format should be reduced. e.g., 2 ,5 ,10 etc.
unit: The part of the date format that needs to be manipulated. e.g., "MINUTE" , "HOUR" , "MONTH" , "YEAR" , "QUARTER" , * "WEEK" , "DAY" , "SECOND"
dateFormat: The date format of the date value provided. e.g., yyyy-MM-dd HH:mm:ss.SSS
timestampInMilliseconds: The date value in milliseconds (from the epoch). e.g., 1415712224000L

Syntax	`<string> dateSub (<string> dateValue , <long> expr, <string> unit, <string> dateFormat )`
Extension Type	Function
Description	Returns the specified date and time with the selected `unit` of the specified `dateValue` reduced by the given amount (i.e. `expr`).
Example	`dateSub("2014-11-11 13:23:44", 2, 'year',"yyyy-MM-dd HH:mm:ss")` returns `"2012-11-11 13:23:44"`.

Syntax	`<string> dateSub (<string> dateValue , < long > expr, <string> unit )`
Extension Type	Function
Description	Returns the specified date and time stamp with he selected `unit`of the specified `dateValue` reduced by the given amount (i.e. `expr`).
Example	`dateSub("2014-11-11 13:23:44", 2, 'year')` returns `"2012-11-11 13:23:44".`

Syntax	`<string> dateSub (<long> timestampInMilliseconds, < long > expr, <string> unit )`
Extension Type	Function
Description	Returns the specified time stamp with the selected `unit`of the specified `timestampInMilliseconds` reduced by the given amount (i.e. `expr`).
Example	`dateSub(1415692424000L, 2, 'year')` returns `1352620424000.`

dateDiff

The common parameters of this function are described below.

dateValue1: A value of date. e.g., "2014-11-11 13:23:44.657", "2014-11-11" , "13:23:44.657"
dateValue2: A value of date. e.g., "2014-11-11 13:23:44.657", "2014-11-11" , "13:23:44.657"
dateFormat1: The date format of dateValue1. e.g., yyyy-MM-dd HH:mm:ss.SSS
dateFormat2: The date format of dateValue2. e.g., yyyy-MM-dd HH:mm:ss.SSS
timestampInMilliseconds1: A date value in milliseconds (from the epoch) e.g., 1415712224000L
timestampInMilliseconds2:A date value in milliseconds (from the epoch) e.g., 1415712224000L

Syntax	`<int> dateDiff (<string> dateValue1 , < string > dateValue2 , <string> dateFormat1, <string> dateFormat2 )`
Extension Type	Function
Description	Returns the number of days between the two dates specified (i.e. `dateValue1` and `dateValue2`).
Example	`dateDiff('2014-11-11 13:23:44', '2014-11-9 13:23:44', 'yyyy-MM-dd HH:mm:ss', 'yyyy-MM-dd HH:mm:ss')` returns `2`.

Syntax	`<int> dateDiff (<string> dateValue1 , < string > dateValue2 )`
Extension Type	Function
Description	Returns the number of days between the two dates specified (i.e. `dateValue1` and `dateValue2`).
Example	`dateDiff('2014-11-11 13:23:44.000', '2014-11-9 13:23:44.000'`) returns `2`.

Syntax	`<int> dateDiff (<string> timestampInMilliseconds1 , < string > timestampInMilliseconds2 )`
Extension Type	Function
Description	Returns the number of days between the two date and time stamps specified (i.e. `timestampInMilliseconds1` and `timestampInMilliseconds2`).
Example	`dateDiff(1415692424000, 1415519624000)` returns `2`.

dateFormat

The common parameters of this function are described below.

dateValue: -A value of date. e.g., "2014-11-11 13:23:44.657", "2014-11-11" , "13:23:44.657"
dateTargetFormat: The date format to which the specified date value needs to be converted. e.g., yyyy/MM/dd HH:mm:ss
dateSourceFormat: The date format of the date value provided. e.g., yyyy-MM-dd HH:mm:ss.SSS
timestampInMilliseconds: A date value in milliseconds (from the epoch) e.g., 1415712224000L

Syntax	`<string> dateFormat(<string> dateValue,<string> dateTargetFormat,<string> dateSourceFormat)`
Extension Type	Function
Description	Returns a formatted date string.
Example	`dateFormat('2014-11-11 13:23:55', 'ss', 'yyyy-MM-dd HH:mm:ss')` returns `55`.

Syntax	`<string> dateFormat(<string> dateValue,<string> dateTargetFormat)`
Extension Type	Function
Description	Returns a formatted date string.
Example	`dateFormat('2014-11-11 13:23:55.657', 'ss')` returns `55`.

Syntax	`<string> dateFormat (<long> timestampInMilliseconds ,<string> dateTargetFormat)`
Extension Type	Function
Description	Returns a formatted date string.
Example	`dateFormat(1415692424000, 'yyyy-MM-dd')` returns `2014-11-11.`

extract

dateValue: A value of date. e.g., "2014-11-11 13:23:44.657", "2014-11-11" , "13:23:44.657"
unit: The part of the date format that needs to be manipulated. e.g., "MINUTE" , "HOUR" , "MONTH" , "YEAR" , "QUARTER" , * "WEEK" , "DAY" , "SECOND"
dateFormat: The date format of the date value provided. e.g., yyyy-MM-dd HH:mm:ss.SSS
timestampInMilliseconds: A date value in milliseconds (from the epoch) e.g., 1415712224000L

Syntax	`<int> extract (<string> unit ,<string> dateValue, <string> dataFormat)`
Extension Type	Function
Description	Returns the specified `unit` extracted from the specified `dateValue`.
Example	`extract('year', '2014-3-11 02:23:44', 'yyyy-MM-dd hh:mm:ss')` returns `2014`.

Syntax	`<int> extract (<string> unit ,<string> dateValue)`
Extension Type	Function
Description	Returns the specified `unit` extracted from the specified `dateValue`.
Example	`extract('year', '2014-3-11 02:23:44.234')` returns `2014`.

Syntax	`<int> extract (<long> timestampInMilliseconds ,<string> unit)`
Extension Type	Function
Description	Returns the specified `unit` extracted from the specified `timestampInMilliseconds`.
Example	`extract(1394484824000, 'year')` returns `2014`.

date

Syntax	`<string> date (<string> dateValue ,<string> dateFormat)`
Extension Type	Function
Description	Returns the date component of the `dateValue`.
Example	`extact('2014-11-11 13:23:44', 'yyyy-MM-dd HH:mm:ss')` returns `2014-11-11`.

timestampInMilliseconds

Syntax	`<long> timestampInMilliseconds ()`
Extension Type	Function
Description	Returns the current time stamp in milliseconds.
Example	`timestampInMilliseconds()` returns `1440160328693`.

Syntax	`<long> timestampInMilliseconds (<string> dateValue)`
Extension Type	Function
Description	Returns the time stamp of the specified `dateValue` in milliseconds. In order to use this function, the date format of the specified `dateValue` should be `yyyy-MM-dd HH:mm:ss.SSS`.
Example	`timestampInMilliseconds('2007-11-30 10:30:19.000')` returns `1196398819000`.

Syntax	`<long> timestampInMilliseconds (<string> dateValue, <string> dateFormat)`
Extension Type	Function
Description	Returns the time stamp of the specified `dateValue` in milliseconds. The date format can be specified in the `dateForma`t parameter.
Example	`timestampInMilliseconds('2007-11-30 10:30:19', 'yyyy-MM-dd HH:mm:ss')` returns `1196398819000`.

utcTimestamp

Syntax	`<string> utcTimestamp()`
Extension Type	Function
Description	Returns the system time in the `yyyy-MM-dd HH:mm:ss` date format.
Example	`utcTimestamp()` returns `2015-08-21 12:16:13`.

nlp
Anchor
nlp
nlp

This extension provides Natural Language Processing capabilities to Siddhi. Functions of the NLP extension are as follows.

findNameEntityType

Syntax	`<string> findNameEntityType(<string> entityType, <bool> groupSuccessiveMatch, <string> string-variable )`
Extension Type	Function
Description	This function uses the following input parameters. `entityType`: This is a user-specified string constant. e.g., `PERSON`, `LOCATION`, `ORGANIZATION`, `MONEY`, `PERCENT`, `DATE` or `TIME` `groupSuccessiveMatch`: This is a user-specified boolean constant used to group successive matches of the specified `entityType` and a text stream. `streamAttribute`: A string or the stream attribute in which text stream is included. This function returns the entities in the text. If you specify group successive matches as `true`, the result aggregates successive words of the same entity type.
Example	`findNameEntityType("PERSON",true,text)` In the above example, if the text attribute contains "`Bill Gates donates £31million to fight Ebola"`, the result is `Bill Gates`. If the group successive match is set to `false`, two events are generated as `Bill` and `Gates`.

findNameEntityTypeViaDictionary

Syntax	`<string> findNameEntityTypeViaDictionary(<string> entityType, <string> dictionaryFilePath, <string> string-variable )`
Extension Type	Function
Description	This function uses the following input parameters. `entityType`: This is a user-specified string constant. e.g., `PERSON`, `LOCATION`, `ORGANIZATION`, `MONEY`, `PERCENT`, `DATE` or `TIME` `dictionaryFilePath`: The path to the dictionary in which the function searches for the specified entries. The relevant entries for the entity types should be available in the dictionary as shown in the example below. `streamAttribute`: A string or the stream attribute in which text stream is included. This function returns the entities in the text. If you specify group successive matches as `true`, the result aggregates successive words of the same entity type.
Example	`findNameEntityTypeViaDictionary("PERSON","dictionary.xml",text)` In the above example, if the text attribute contains `"Bill Gates donates £31million to fight Ebola"`, and the dictionary consists of the above entries (i.e. entries of the example in the Description), the result is `"Bill"`.

findRelationshipByVerb

Syntax	`<string > text, <string> subject, < string > object < string > verb findRelationshipByVerb (<string> verb, <string> string-variable )`
Extension Type	Function
Description	`findRelationshipByVerb` takes in a user specified string constant as a verb and a text stream, and returns the whole text, subject, object and the verb based on the specified verb. This information can be extracted only if the verb specified exists in the text stream. However, the tense of the verb does not have to match. The input parameters used are as follows. `verb`: This is a user specified string constant. `string-variable`: A string or the stream attribute which includes the text stream.
Examples	`findRelationshipByVerb("say", "Information just reaching us says another Liberian With Ebola Arrested At Lagos Airport")` returns the following. The whole text `Information` as the subject `Liberian` as the object. `says` as the verb.

findRelationshipByRegex

Syntax	`<string > text, <string> subject, < string > object < string > verb findRelationshipByRegex (<string> regex, <string> string-variable )`
Extension Type	Function
Description	This function returns the whole text, subject, object and verb from the text stream that matches the named nodes of the Semgrex pattern.
Example	`findRelationshpByRegex('{}=verb >/nsubj\|agent/ {}=subject >/dobj/ {}=object', "gates foundation donates $50M in support of #Ebola relief")` returns the following. The whole text `"foundation"` as the subject `"$"` as the object `"donates"` as the verb

findSemgrexPattern

Syntax	`<string > text, <string> match, < string > object < string > verb findSemgrexPattern (<string> regex, <string> string-variable )`
Extension Type	Function
Description	The `findSemgrexPattern` function returns the whole text, subject, object and verb from the text stream that matches the named nodes of the Semgrex pattern. This function uses the following input parameters. `regex`: A user specified regular expression that matches the Semgrex pattern syntax. `string-variable`: A string or the stream attribute which includes the text stream.
Example	`findSemgrexPattern('{lemma:die} >/.subj\|num./=reln {}=diedsubject', "Sierra Leone doctor dies of Ebola after failed evacuation.")` In this example, the function searches for words with the lemmatization `die` that are governors on any subject or numeric relation. The dependent is marked as the `diedsubject`, and the relationship is marked as `reln`. Thus, the query returns an output stream that has the full match of this expression, i.e. the governing word with lemmatization for `die`. It also returns the name of the corresponding node for each match it finds. The following is the list of elements in the output stream. The whole text `dies` as the match `"nsubj"` as `reln` `doctor` asdiedsubject

findTokensRegexPattern

Syntax	`< string > text, <string> match, <string> group_1, etc. findTokensRegexPattern (<string> regex, <string> string-variable )`
Extension Type	Function
Description	`findTokensRegexPattern` returns the whole text, subject, object and verb from the text stream that matches the named nodes of the Semgrex pattern. The return also includes the corresponding node in the Semgrex pattern and the corresponding named relation defined in the regular expression for each word/phrase. This function uses the following input parameters. `regex`: A user specified regular expression that matches the Semgrex pattern syntax. `string-variable`: A string or the stream attribute which includes the text stream.
Example	`findTokensRegexPattern('([ner:/PERSON\|ORGANIZATION\|LOCATION/]+) (?:[]* [lemma:donate]) ([ner:MONEY]+)', text)` defines three groups: The first group looks for words that are entities of either `PERSON`, `ORGANIZATON` or `LOCATION` with one or more successive words matching same. The middle group is defined as the non capturing group. Third looks for one or more successive entities of type `MONEY`. This function returns the following. `The whole text` `" Paul Allen donates $ 9million "` as the match. `" Paul Allen"`, as group_1. `"$ 9million"` as group_2.

pmml
Anchor
pmml
pmml

This extension adds PMML based predictive analytic model compliance to Siddhi. It allows you to make predictions based on a predictive analytic model. Supported functions of PMML extension are as follows.

predict

Syntax	`< double \| float\|long\|int\|string\|boolean > predict(<string> pathToPmmlFile)`
Extension Type	Stream Processor
Description	Processes the input stream attributes according to the defined PMML standard model and outputs the processed results together with the input stream attributes. This function uses the following input parameter. `pathToPmmlFile`: The path to the PMML model file. The function returns the outputs defined in the output fields. The number of outputs can vary.
Example	`predict('<CEP HOME>/samples/artifacts/0301/decision-tree.pmml')` This model is implemented to detect network intruders. The input event stream is processed by the execution plan that uses the pmml predictive model to detect whether a particular user is an intruder to the network or not. The output stream contains the processed query results that include the predicted responses together with the feature values extracted from the input event stream.

Syntax	`< double \| float\|long\|int\|string\|boolean > predict(<string> pathToPmmlFile, <double\|float\|long\|int\|string\|boolean> input )`
Extension Type	Stream Processor
Description	Processes the input stream attributes according to the defined PMML standards model and outputs the processed results. This function uses the following input parameters. `pathToPmmlFile`: The path to the PMML model file. `input`: An attribute of the input stream that is sent to the PMML standard model as a value to based on which the prediction is made. The `predict` function does not accept any constant values as input parameters. You can have multiple input parameters according to the input stream definition. This function returns the processed outputs defined in the query. The number of outputs can vary depending on the query definition.
Examples	`predict('<CEP HOME>/samples/artifacts/0301/decision-tree.pmml', root_shell double, su_attempted double, num_root double, num_file_creations double, num_shells double, num_access_files double, num_outbound_cmds double, is_host_login double, is_guest_login double , count double, srv_count double, serror_rate double, srv_serror_rate double)` This model is implemented to detect network intruders. The input event stream is processed by the execution plan that uses the pmml predictive model to detect whether a particular user is an intruder to the network or not. The output stream contains the processed query results that include the predicted responses.

...

See Time Series Extension.

kf (Kalman Filter)

This extension provides Kalman filtering capabilities to Siddhi. This allows you to detect outliers of input data. Following are the functions of the Kalman Filter extension.

kalmanFilter

This function uses measurements observed over time containing noise and other inaccuracies, and produces estimated values for the current measurement.

Syntax	`<double, double> kalmanFilter(<double> measuredValue)`
Extension Type	Fuction
Example	1st round: `kf:kalmanFilter(-74.178444)` returns an estimated value of `-74.178444`. 2nd round: `kf:kalmanFilter(-74.177872)` returns an estimated value of `-74.178158000143`. 3rd round: `kf:kalmanFilter(-74.175703)` returns an estimated value of `-74.1773396670348.`

Syntax	`<double, double> kalmanFilter(<double> measuredValue, <double> measurementNoiseSD)`
Extension Type	Function
Example	1st round: `kf:kalmanFilter(-74.178444)` returns an estimated value of `-74.178444`. 2nd round: `kf:kalmanFilter(-74.177872)` returns an estimated value of `-74.17815800142999`. 3rd round: `kf:kalmanFilter(-74.175703)` returns an estimated value of `-74.17733967034776`.

Syntax	`<double, double> kalmanFilter(<double> measuredValue, <double> measuredChangingRate, <double> measurementNoiseSD, <long> timestamp)`
Extension Type	Function
Example	1st round: `kf:kalmanFilter(-74.178444)` returns an estimated value of `-74.1784439700006`. 2nd round: `kf:kalmanFilter(-74.177872)` returns an estimated value of `-74.17657538193608`. 3rd round: `kf:kalmanFilter(-74.175703)` returns an estimated value of `-74.17487924016262`.

map

This extension provides the capability to send a map object inside Siddhi stream definitions and use it inside queries. The following are the functions of the map extension.

create

Syntax	`<Object> create()` or `<Object> create(<Object> key1, <Object> value1,<Object> key2, <Object> value2,...<Object> keyN, <Object> valueN)`
Extension Type	Function
Description	Returns the created map object.
Examples	`create()` returns an empty map. `create(1 , ”one” , 2 , ”two” , 3 , ”three”)` returns a map with keys `1, 2, 3` and corresponding values `"one", "two", "three"`.

get

Syntax	`<Object> get(<Map> map, <Object> key)`
Extension Type	Function
Description	Returns the value object from the map that is related to the given key.
Example	`get(company,1)` returns the value that is related to the key `1` from the map named `company`.

isMap

Syntax	`<bool> isMap(<Object> object)`
Extension Type	Function
Description	Returns `true` if the object is a map or `false` otherwise.
Example	`isMap(students)` returns `true` if the students object is a map. It returns `false` if the `students` object is not a map.

put

Syntax	`Object> put(<Object> map, <Object> key,<Object> value)`
Extension Type	Function
Description	Returns the updated map after adding the given key-value pair.
Example	`put(students , 1234 , ”sam”)` returns the updated map named `students` after adding the object `"sam"` with key `1234`.

remove

Syntax	`<Object> remove(<Object> map, <Object> key)`
Extension Type	Function
Description	Returns the updated map after removing the element with key.
Example	`remove(students , 1234)` returns the updated map `students` after removing the element with the key `1234`.

createFromJSON

Syntax	`<Object> createFromJSON(<string> JSONstring)`
Extension Type	Function
Description	Returns the map created with the key values pairs given in the `JSONstring`.
Example	`createFromJSON(“{‘symbol' : 'IBM' , 'price' : 200, 'volume' : 100}”)` returns a map with the keys "`symbol"`, `"price", "volume"`, and with the values `"IBM"`, `200` and `100` respectively.

createFromXML

Syntax	`<Object> createFromXML(<string> XMLstring)`
Extension Type	Function
Description	Returns the map created with the key values pairs given in the XMLstring.
Example	`createFromXML(“<company> <symbol> wso2 </symbol> <price> <100> </price> <volume> 200 </volume> </company>”)` returns a map with the keys `"symbol"`, `"price"`, `"volume"`, and with the values `WSO2`, `100` and `200` respectively.

toJSON

Syntax	`<String> toJSON(<Object> map)`
Extension Type	Function
Description	Converts a map into a JSON object and returns the definition of that JSON object as a string.
Example	If `"company"` is a map with key value pairs `("symbol" : wso2)`, `("volume" : 100)`, and `("price",200)`, `toJSON(company)` returns the string `“{“symbol” : “wso2” , “volume” : 100 , “price” : 200}”`.

toXML

Syntax	`<String> toXML(<Object> map)`
Extension Type	Function
Description	Returns the map as an XML string.
Example	If `"company"` is a map with key value pairs `(“symbol” : wso2)`, `(“volume” : 100)`, and `(“price” : 200),` `toXML(company)` returns the string `“<symbol>wso2</symbol><volume><100></volume><price>200</price>"`.

reorder

Reorder extension is implemented using the K-Slack algorithm. The K-Slack Siddhi extension is used for reordering events from an unordered event stream. The following is an example of a query with the reorder extension.

Code Block

language	sql
linenumbers	true

@info(name = 'query1') 
from inputStream#reorder:kslack(eventTimestamp) 
select eventTimestamp, price, volume 
insert into outputStream;

There are several important variations of the K-slack API of which the details are described below.

kslack

Syntax	`<bool> kslack(<long> timestamp)`
Extension Type	StreamProcessor
Description	This is the most basic version. The events are sorted by the `timestamp` parameter.

Syntax	`<bool> kslack(<long> timestamp, <long> timeOut )`
Extension Type	StreamProcessor
Description	The second argument shown in the above syntax corresponds to a fixed time-out value set at the beginning of the process. Once the time-out value expires, the extension drains all the events that are buffered within the reorder extension to outside. The time out has been implemented internally using a timer. The events buffered within the extension are released each time the timer ticks.

Syntax	<bool> kslack(<long> timestamp, <long> timeOut, <long> maxValue )
Extension Type	StreamProcessor
Description	The third argument in the above syntax is the maximum value for K. This is the amount to which the K value of the K-Slack algorithm will be increased.
Example	`kslack(timestamp, -1l, 1000000)` In the above example, the algorithm execution starts when K=0 and it gets increased up to 1000000. The value of the `K-slack` does not increase from that point onwards. Hence, this leads to lower latency compared to the version shown in the first (i.e., single parameter) example of this list. Note that the second argument is set to `-1l` which effectively disables the timer based draining of the internal buffer. `kslack(timestamp, 1000l, 1000000)` The above is another variation of the third category. Here, a time-out value is specified for the second argument (i.e. 1000 ms). In this case, the K-slack algorithm buffers events until the 1000ms time period expires. The maximum K value is 1000000. The K-value cannot exceed the specified amount.

Syntax	`<bool> kslack(<long> timestamp, <long> timeOut, <bool> expireFlag )`
Extension Type	StreamProcessor
Description	The fourth argument in the above syntax is a flag that indicates whether the out-of order events that appear after the expiration of the K-slack window should be discarded or not.
Example	`kslack(timestamp, -1l, -1l, true)`

prerequisites

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Key

functionName

functionName

acos

atan

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power

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regexp

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strcmp

r AnchorRR

regex Anchorregexregex

find

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matches Anchormatchmatch

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findNameEntityTypeViaDictionary

findRelationshipByVerb

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pmml Anchorpmmlpmml

predict

kf (Kalman Filter)

kalmanFilter

map

create

get

isMap

put

remove

createFromJSON

createFromXML

toJSON

toXML

reorder

kslack

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