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API Docs - v4.0.15

R

eval (Stream Processor)

The R Script Stream Processor runs the R script defined within the Siddhi application to each event and produces aggregated outputs based on the input variable parameters provided and the expected output attributes.

Syntax

r:eval(<STRING> script, <INT|LONG|FLOAT|DOUBLE|STRING|STRING> output.attributes, <INT|LONG|FLOAT|DOUBLE|STRING|STRING> input.attributes)

QUERY PARAMETERS

Name	Description	Possible Data Types	Optional	Dynamic
script	The R script as a string which produces aggregated outputs based on the provided input variable parameters and the expected output attributes	STRING	No	No
output.attributes	The expected set of output attributes. These can be provided as a comma-separated list. Each attribute is denoted as '<name><space><type>'. e.g., 'output1 string, output2 long'.	INT LONG FLOAT DOUBLE STRING STRING	No	No
input.attributes	A set of input attributes to be considered when generating the expected output. This can be provided as a comma-separated list after output attributes. e.g., 'att1, att2'.	INT LONG FLOAT DOUBLE STRING STRING	No	No

Extra Return Attributes

Name	Description	Possible Types
outputParameters	The output parameters returned once the R script is run for each event.	INT LONG FLOAT DOUBLE STRING STRING

Examples EXAMPLE 1

@info(name = 'query1')
from weather#window.lengthBatch(2)#r:eval("c <- sum(time); m <- sum(temp); ", "c long, m double", time, temp) 
select * 
insert into dataOut;

This query runs the R script 'c <- sum(time); m <- sum(temp);' for every two events in a tumbling manner. Values are derived for two output parameters named 'c' and 'm' by considering the values of two other parameters named 'time' and 'temp' as the input.

evalSource (Stream Processor)

The R source Stream processor runs the R script loaded from a file for each event and produces aggregated outputs based on the input variable parameters provided and the expected output attributes.

Syntax

r:evalSource(<STRING> file.path, <INT|LONG|FLOAT|DOUBLE|STRING|STRING> output.attributes, <INT|LONG|FLOAT|DOUBLE|STRING|STRING> input.attributes)

QUERY PARAMETERS

Name	Description	Possible Data Types	Optional	Dynamic
file.path	The file path of the R script where this script is located uses the input variable parameters and produces the expected output attributes.	STRING	No	No
output.attributes	The expected output attributes. This can be provided and a string of comma-separated attribute names. Each attribute is denoted as <name><space><type>. e.g., 'output1 string, output2 long'.	INT LONG FLOAT DOUBLE STRING STRING	No	No
input.attributes	A set of input attributes to be considered when generating the expected output. This can be provided as a comma-separated list after output attributes. e.g., 'att1, att2'.	INT LONG FLOAT DOUBLE STRING STRING	No	No

Extra Return Attributes

Name	Description	Possible Types
outputParameters	The output parameters returned once the R script is run for each event.	INT LONG FLOAT DOUBLE STRING STRING

Examples EXAMPLE 1

@info(name = 'query1')
from weather#window.lengthBatch(2)#r:evalSource("src/test/resources/sample2.R", "m int, c float", time, temp)
select *
insert into dataOut;

This 'r' source function takes in a 'r' script file location and computes the output as defined in the file.