Package opennlp.tools.ml.model

Class RealValueFileEventStream

java.lang.Object

opennlp.tools.ml.model.FileEventStream

opennlp.tools.ml.model.RealValueFileEventStream

All Implemented Interfaces:

AutoCloseable, ObjectStream<Event>

public class RealValueFileEventStream
extends FileEventStream

Class for using a file of real-valued events as an event stream. The format of the file is one event per line with each line consisting of outcome followed by contexts (space delimited).

See Also:

• Event
• FileEventStream

Constructor Summary

Constructors

Constructor	Description
RealValueFileEventStream(File file)	Instantiates a RealValueFileEventStream via a File.
RealValueFileEventStream(Reader reader)	Instantiates a RealValueFileEventStream via a Reader.
RealValueFileEventStream(String fileName)	Instantiates a RealValueFileEventStream from the specified file name.
RealValueFileEventStream(String fileName, String encoding)	Instantiates a RealValueFileEventStream from the specified file name.

Method Summary

Modifier and Type	Method	Description
static float[]	parseContexts(String[] contexts)	Parses the specified contexts and re-populates context array with features and returns the values for these features.
Event	read()	Returns the next Event object.

Methods inherited from class opennlp.tools.ml.model.FileEventStream

close, reset, toLine

Methods inherited from class java.lang.Object

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

Constructor Details

RealValueFileEventStream

public RealValueFileEventStream(String fileName)
                         throws IOException

Instantiates a RealValueFileEventStream from the specified file name.

Parameters:

fileName - The name fo the file containing the events.

Throws:

IOException - Thrown if the specified file can not be read.

RealValueFileEventStream

public RealValueFileEventStream(String fileName,
 String encoding)
                         throws IOException

Instantiates a RealValueFileEventStream from the specified file name.

Parameters:

fileName - The name fo the file containing the events.

encoding - The name of the character encoding.

Throws:

IOException - Thrown if the specified file can not be read.

RealValueFileEventStream

public RealValueFileEventStream(File file)
                         throws IOException

Instantiates a RealValueFileEventStream via a File.

Parameters:

file - The File that holds events.

Throws:

IOException - Thrown if the specified file can not be read.

RealValueFileEventStream

public RealValueFileEventStream(Reader reader)
                         throws IOException

Instantiates a RealValueFileEventStream via a Reader.

Parameters:

reader - The Reader that holds events.

Throws:

IOException - Thrown if the specified file can not be read.

Method Details

parseContexts

public static float[] parseContexts(String[] contexts)

Parses the specified contexts and re-populates context array with features and returns the values for these features. If all values are unspecified, then null is returned.

Parameters:

contexts - The contexts with real values specified.

Returns:

The value for each context or null if all values are unspecified.

Throws:

RuntimeException - Thrown if negative real values are detected in the input data.

read

public Event read()
           throws IOException

Returns the next Event object. Calling this method repeatedly until it returns null will return each object from the underlying source exactly once.

Specified by:

read in interface ObjectStream<Event>

Overrides:

read in class FileEventStream

Returns:

The next object or null to signal that the stream is exhausted.

Throws:

IOException - Thrown if there is an error during reading.

RuntimeException - Thrown if negative real values are detected in the input data.