org.opennms.netmgt.integrations.R

Class RScriptExecutor

java.lang.Object

org.opennms.netmgt.integrations.R.RScriptExecutor

public class RScriptExecutor
extends Object

The RScriptExecutor provides an interface for invoking R scripts via system commands. This provides a simple alternative to using rJava, which relies on JNI bits. The interface supports passing and retrieving values in a tabular format, as well as arbitrary arguments. The values are sent and retrieved from the script via stdin/stdout. The arguments are baked into the script using Freemarker tags.

Author:

jwhite

Field Summary

Fields

Modifier and Type	Field and Description
static String	RSCRIPT_BINARY The Rscript binary used to execute the .R scripts.
static long	SCRIPT_TIMEOUT_MS Maximum runtime of the Rscript process in milliseconds before failing and throwing an exception.

Constructor Summary

Constructors

Constructor and Description
RScriptExecutor()

Method Summary

Methods

Modifier and Type	Method and Description
RScriptOutput	exec(String script, RScriptInput input) Executes by given script by: - Searching both the classpath and the filesystem for the path - Copying the script at the given path to a temporary file and performing variable substitution with the arguments using Freemarker.
protected static com.google.common.collect.ImmutableTable<Integer,String,Double>	fromCsv(String csv) Convert the CSV string to an immutable table.
protected static StringBuilder	toCsv(com.google.common.collect.RowSortedTable<Integer,String,Double> table) Convert the table to a CSV string.

Methods inherited from class java.lang.Object

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

Field Detail

RSCRIPT_BINARY

public static final String RSCRIPT_BINARY

The Rscript binary used to execute the .R scripts.

SCRIPT_TIMEOUT_MS

public static final long SCRIPT_TIMEOUT_MS

Maximum runtime of the Rscript process in milliseconds before failing and throwing an exception.

See Also:

Constant Field Values

Constructor Detail

RScriptExecutor

public RScriptExecutor()

Method Detail

exec

public RScriptOutput exec(String script,
                 RScriptInput input)
                   throws RScriptException

Executes by given script by: - Searching both the classpath and the filesystem for the path - Copying the script at the given path to a temporary file and performing variable substitution with the arguments using Freemarker. - Invoking the script with commons-exec - Converting the input table to CSV and passing this to the process via stdin - Parsing stdout, expecting CSV output, and converting this to an immutable table

Throws:

RScriptException

fromCsv

protected static com.google.common.collect.ImmutableTable<Integer,String,Double> fromCsv(String csv)
                                                                                  throws IOException

Convert the CSV string to an immutable table.

Throws:

IOException

toCsv

protected static StringBuilder toCsv(com.google.common.collect.RowSortedTable<Integer,String,Double> table)
                              throws IOException

Convert the table to a CSV string.

Throws:

IOException