edu.udo.cs.yale.operator.io
Class SimpleExampleSource

java.lang.Object
  edu.udo.cs.yale.operator.Operator
      edu.udo.cs.yale.operator.io.SimpleExampleSource

All Implemented Interfaces:

ConfigurationListener

public class SimpleExampleSource
extends Operator

This operator reads an example set from (a) file(s). Probably you can use the default parameter values for the most file formats (including the format produced by the ExampleSetWriter, CSV, ...). In fact, in many cases this operator is more appropriate for CSV based file formats than the CSVExampleSource operator itself.

In contrast to the usual ExampleSource operator this operator is able to read the attribute names from the first line of the data file. However, there are some restrictions: the data can only be read from one file instead of multiple files, all attributes must have the same value type, and currently the only special attribute which is supported is a single label attribute. If you need other functionality you should use the more powerful ExampleSource operator.

The split points can be defined with regular expressions (please refer to the Java API). The default split parameter ",\s*|;\s*|\s+" should work for most file formats. This regular expression describes the following column separators

• the character "," followed by a whitespace of arbitrary length (also no white space)
• the character ";" followed by a whitespace of arbitrary length (also no white space)
• a whitespace of arbitrary length (min. 1)

A logical XOR is defined by "|". Other useful separators might be "\t" for tabulars, " " for a single whitespace, and "\s" for any whitespace.

Quoting is also possible with ". However, using quotes slows down parsing and is therefore not recommended. The user should ensure that the split characters are not included in the data columns and that quotes are not needed. Additionally you can specify comment characters which can be used at arbitrary locations of the data lines. Unknown attribute values can be marked with empty strings or a question mark.

Version:

$Id: SimpleExampleSource.java,v 1.8 2006/04/12 18:04:24 ingomierswa Exp $

Author:

Ingo Mierswa

Keywords:

csv

Field Summary

private static java.lang.Class[]	INPUT_CLASSES
private static java.lang.Class[]	OUTPUT_CLASSES

Constructor Summary

SimpleExampleSource(OperatorDescription description)

Method Summary

IOObject[]	apply() Implement this method in subclasses.
java.lang.Class[]	getInputClasses() Returns the classes that are needed as input.
java.lang.Class[]	getOutputClasses() Returns the classes that are guaranteed to be returned by apply() as additional output.
java.util.List<ParameterType>	getParameterTypes() Returns a list of ParameterTypes describing the parameters of this operator.
private void	resetAttributeType(java.util.List<AttributeDataSource> attributeDataSources, java.lang.String columnName, java.lang.String typeName)

Methods inherited from class edu.udo.cs.yale.operator.Operator

addError, addValue, addWarning, apply, checkDeprecations, checkIO, checkProperties, clearErrorList, cloneOperator, createExperimentTree, createExperimentTree, createFromXML, createMarkedExperimentTree, delete, experimentFinished, experimentStarts, getAddOnlyAdditionalOutput, getApplyCount, getDeliveredOutputClasses, getDeprecationInfo, getDesiredInputClasses, getErrorList, getExperiment, getInnerOperatorsXML, getInput, getInput, getInput, getInputDescription, getIOContainerForInApplyLoopBreakpoint, getName, getNumberOfSteps, getOperatorClassName, getOperatorDescription, getParameter, getParameterAsBoolean, getParameterAsColor, getParameterAsDouble, getParameterAsFile, getParameterAsInt, getParameterAsString, getParameterList, getParameters, getParameterType, getParent, getStartTime, getStatus, getUserDescription, getValue, getValues, getXML, hasBreakpoint, hasBreakpoint, hasInput, inApplyLoop, isEnabled, isParameterSet, logMessage, performAdditionalChecks, register, remove, rename, resume, setBreakpoint, setEnabled, setExperiment, setInput, setListParameter, setOperatorParameters, setParameter, setParameters, setParent, setUserDescription, toString, writeXML

Methods inherited from class java.lang.Object

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

Field Detail

INPUT_CLASSES

private static final java.lang.Class[] INPUT_CLASSES

OUTPUT_CLASSES

private static final java.lang.Class[] OUTPUT_CLASSES

Constructor Detail

SimpleExampleSource

public SimpleExampleSource(OperatorDescription description)

Method Detail

apply

public IOObject[] apply()
                 throws OperatorException

Description copied from class: Operator

Implement this method in subclasses.

Specified by:

apply in class Operator

Throws:

OperatorException

resetAttributeType

private void resetAttributeType(java.util.List<AttributeDataSource> attributeDataSources,
                                java.lang.String columnName,
                                java.lang.String typeName)
                         throws OperatorException

Throws:

OperatorException

getInputClasses

public java.lang.Class[] getInputClasses()

Description copied from class: Operator

Returns the classes that are needed as input. May be null or an empty (no desired input). As default, all delivered input objects are consumed and must be also delivered as output in both Operator.getOutputClasses() and Operator.apply() if this is necessary. This default behavior can be changed by overriding Operator.getInputDescription(Class). Subclasses which implement this method should not make use of parameters since this method is invoked by getParameterTypes(). Therefore, parameters are not fully available at this point of time and this might lead to exceptions. Please use InputDescriptions instead.

Specified by:

getInputClasses in class Operator

getOutputClasses

public java.lang.Class[] getOutputClasses()

Description copied from class: Operator

Returns the classes that are guaranteed to be returned by apply() as additional output. Please note that input object which should not be consumed must also be defined by this method (e.g. for preprocessing operators). The default behavior for input consumation is defined by Operator.getInputDescription(Class) and can be changed by overwriting this method. Objects which are not consumed must not be defined as additional output in this method. May be null or an empy array (no additional output is produced).

Specified by:

getOutputClasses in class Operator

getParameterTypes

public java.util.List<ParameterType> getParameterTypes()

Description copied from class: Operator

Returns a list of ParameterTypes describing the parameters of this operator. The default implementation returns an empty list if no input objects can be retained and special parameters for those input objects which can be prevented from being consumed.

Overrides:

getParameterTypes in class Operator