com.pervasive.datarush.analytics.r

Class RunRScript

java.lang.Object

com.pervasive.datarush.operators.AbstractLogicalOperator

com.pervasive.datarush.operators.CompositeOperator

com.pervasive.datarush.analytics.r.RunRScript

All Implemented Interfaces:

LogicalOperator, PipelineOperator<RecordPort>, RecordPipelineOperator

public class RunRScript
extends CompositeOperator
implements RecordPipelineOperator

Execute an R script in flow. The input data will be presented to the R script as the data frame named "R". The data frame with the same name ("R") will be used to write to the output. CSV format is used to import data into R and export data from R. The auto-discovery mechanism of R when reading CSV data is relied upon to handle data typing.

This operator is parallelized by default. This implies that multiple R instances are initialized and the given script is executed within each instance with a different segment of the input data. Disable parallelism for the operator if any data dependencies exist due to R functions used in the script.

Two variables are initially set within the R environment prior to execution within each operator instance:

• partitionID: zero-based identifier of the instance partition
• partitionCount: the total number of data partitions created to execute the current graph

The variables can be used to differentiate the current partition of the current instance and the overall partition count. This information can be used within the script to base the script behavior on the execution environment.

Use the setPathToRScript(String) method to set the path to the Rscript executable. This executable is used instead of the R executable as it is meant to run a single R script specified on the command line.

Constructor Summary

Constructors

Constructor and Description
RunRScript()

Method Summary

Methods

Modifier and Type	Method and Description
protected void	compose(CompositionContext ctx) Compose the body of this operator.
static String	getIdentifierRegex() Function to return a Regular Expression string that can be used to identify a valid R identifier.
RecordPort	getInput() Returns the input port
RecordPort	getOutput() Returns the output port
RecordTokenType	getOutputType() Get the configured output type.
String	getPathToRScript() Get the path to the Rscript binary within the local R installation.
DataDistribution	getRequiredDataDistribution() Get the value set for the required data distribution of the input port of this operator.
String	getScriptSnippet() Get the R script to execute.
void	setOutputType(RecordTokenType outputType) Configure the output token type.
void	setPathToRScript(String pathToRScript) Set the path to the Rscript binary within the local R installation.
void	setRequiredDataDistribution(DataDistribution dataDistribution) Set the data distribution requirements for the input port of this operator.
void	setScriptSnippet(String scriptSnippet) Set the R script to execute.
static String	validateFieldName(int position, String fldName) Function to ensure an input/output field name conforms to R variable identifier requirements.

Methods inherited from class com.pervasive.datarush.operators.AbstractLogicalOperator

disableParallelism, getInputPorts, getOutputPorts, newInput, newInput, newOutput, newRecordInput, newRecordInput, newRecordOutput, notifyError

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.pervasive.datarush.operators.LogicalOperator

disableParallelism, getInputPorts, getOutputPorts

Constructor Detail

RunRScript

public RunRScript()

Method Detail

getInput

public RecordPort getInput()

Description copied from interface: PipelineOperator

Returns the input port

Specified by:

getInput in interface PipelineOperator<RecordPort>

Returns:

the input port

getOutput

public RecordPort getOutput()

Description copied from interface: PipelineOperator

Returns the output port

Specified by:

getOutput in interface PipelineOperator<RecordPort>

Returns:

the output port

getOutputType

public RecordTokenType getOutputType()

Get the configured output type.

Returns:

output record token type

setOutputType

public void setOutputType(RecordTokenType outputType)

Configure the output token type. This is a required property. The type cannot be discovered since the output is determined by the code of the given script.

Parameters:

outputType - output record token type

getPathToRScript

public String getPathToRScript()

Get the path to the Rscript binary within the local R installation.

Returns:

path to RScript executable

setPathToRScript

public void setPathToRScript(String pathToRScript)

Set the path to the Rscript binary within the local R installation. This executable is normally found in the bin directory of the R installation. If this operator is executed on a cluster, R must be installed on each machine within the cluster in a consistent location.

Parameters:

pathToRScript - path to RScript executable

getScriptSnippet

public String getScriptSnippet()

Get the R script to execute.

Returns:

R script

setScriptSnippet

public void setScriptSnippet(String scriptSnippet)

Set the R script to execute.

Parameters:

scriptSnippet -

setRequiredDataDistribution

public void setRequiredDataDistribution(DataDistribution dataDistribution)

Set the data distribution requirements for the input port of this operator. Since this scripting operator has no way to determine what a script may do, specifying the required data distribution allows the operator user to force the distribution requirements of the input port.

Parameters:

dataDistribution - input data distribution

getRequiredDataDistribution

public DataDistribution getRequiredDataDistribution()

Get the value set for the required data distribution of the input port of this operator.

Returns:

required data distribution property (may be null)

compose

protected void compose(CompositionContext ctx)

Description copied from class: CompositeOperator

Compose the body of this operator. Implementations should do the following:

1. Perform any validation of configuration, input types, etc
2. Instantiate and configure sub-operators, adding them to the provided context via the method OperatorComposable.add(O)
3. Create necessary connections via the method OperatorComposable.connect(P, P). This includes connections from the composite's input ports to sub-operators, connections between sub-operators, and connections from sub-operators output ports to the composite's output ports

Specified by:

compose in class CompositeOperator

Parameters:

ctx - the context

validateFieldName

public static String validateFieldName(int position,
                       String fldName)

Function to ensure an input/output field name conforms to R variable identifier requirements. If the field name is not valid, performs the following standardization on the field to produce a valid identifier. This is provided as a convenience for proper identifier formatting within scripts. Input and output schemas set on this operator undergo name validation so this is a mechanism that can be used to ensure identifier referencing is consistent.

Parameters:

position - the ordinal position of the field in the source/target schema - may be needed to disambiguate field names after character substitution takes place.

fldName - the name of the field being validated

Returns:

an R compliant variable identifier

getIdentifierRegex

public static String getIdentifierRegex()

Function to return a Regular Expression string that can be used to identify a valid R identifier. The string returned here is used internally for the validateFieldName function.

Returns:

the Regular Expression string used to identify an R compliant identifier