com.rapidminer.operator.io
Class ArffExampleSource

java.lang.Object
  com.rapidminer.operator.Operator
      com.rapidminer.operator.io.AbstractReader<ExampleSet>
          com.rapidminer.operator.io.AbstractExampleSource
              com.rapidminer.operator.io.ArffExampleSource

All Implemented Interfaces:

ConfigurationListener, PreviewListener, ParameterHandler, LoggingHandler

public class ArffExampleSource
extends AbstractExampleSource

This operator can read ARFF files known from the machine learning library Weka. An ARFF (Attribute-Relation File Format) file is an ASCII text file that describes a list of instances sharing a set of attributes. ARFF files were developed by the Machine Learning Project at the Department of Computer Science of The University of Waikato for use with the Weka machine learning software.

ARFF files have two distinct sections. The first section is the Header information, which is followed the Data information. The Header of the ARFF file contains the name of the relation (@RELATION, ignored by RapidMiner) and a list of the attributes, each of which is defined by a starting @ATTRIBUTE followed by its name and its type.

Attribute declarations take the form of an orderd sequence of @ATTRIBUTE statements. Each attribute in the data set has its own @ATTRIBUTE statement which uniquely defines the name of that attribute and it's data type. The order the attributes are declared indicates the column position in the data section of the file. For example, if an attribute is the third one declared all that attributes values will be found in the third comma delimited column.

The possible attribute types are:

• numeric
• integer
• real
• {nominalValue1,nominalValue2,...} for nominal attributes
• string for nominal attributes without distinct nominal values (it is however recommended to use the nominal definition above as often as possible)
• date [date-format] (currently not supported by RapidMiner)

Valid examples for attribute definitions are
@ATTRIBUTE petalwidth REAL
@ATTRIBUTE class {Iris-setosa,Iris-versicolor,Iris-virginica}

The ARFF Data section of the file contains the data declaration line @DATA followed by the actual example data lines. Each example is represented on a single line, with carriage returns denoting the end of the example. Attribute values for each example are delimited by commas. They must appear in the order that they were declared in the header section (i.e. the data corresponding to the n-th @ATTRIBUTE declaration is always the n-th field of the example line). Missing values are represented by a single question mark, as in:
4.4,?,1.5,?,Iris-setosa

A percent sign (%) introduces a comment and will be ignored during reading. Attribute names or example values containing spaces must be quoted with single quotes ('). Please note that the sparse ARFF format is currently only supported for numerical attributes. Please use one of the other options for sparse data files provided by RapidMiner if you also need sparse data files for nominal attributes.

Please have a look at the Iris example ARFF file provided in the data subdirectory of the sample directory of RapidMiner to get an idea of the described data format.

Author:

Ingo Mierswa Exp $

Keywords:

arff

Field Summary

static java.lang.String	PARAMETER_DATA_FILE The parameter name for "The path to the data file.
static java.lang.String	PARAMETER_DATAMANAGEMENT The parameter name for "Determines, how the data is represented internally.
static java.lang.String	PARAMETER_DECIMAL_POINT_CHARACTER The parameter name for "Character that is used as decimal point.
static java.lang.String	PARAMETER_ID_ATTRIBUTE The parameter name for "The (case sensitive) name of the id attribute"
static java.lang.String	PARAMETER_LABEL_ATTRIBUTE The parameter name for "The (case sensitive) name of the label attribute"
static java.lang.String	PARAMETER_LOCAL_RANDOM_SEED The parameter name for "Use the given random seed instead of global random numbers (only for permutation, -1: use global).
static java.lang.String	PARAMETER_SAMPLE_RATIO The parameter name for "The fraction of the data set which should be read (1 = all; only used if sample_size = -1)"
static java.lang.String	PARAMETER_SAMPLE_SIZE The parameter name for "The exact number of samples which should be read (-1 = use sample ratio; if not -1, sample_ratio will not have any effect)"
static java.lang.String	PARAMETER_WEIGHT_ATTRIBUTE The parameter name for "The (case sensitive) name of the weight attribute"

Constructor Summary

ArffExampleSource(OperatorDescription description)

Method Summary

ExampleSet	createExampleSet() Creates (or reads) the ExampleSet that will be returned by AbstractReader.apply().
java.util.List<ParameterType>	getParameterTypes() Returns a list of ParameterTypes describing the parameters of this operator.

Methods inherited from class com.rapidminer.operator.io.AbstractExampleSource

read

Methods inherited from class com.rapidminer.operator.io.AbstractReader

apply, getInputClasses, getOutputClasses

Methods inherited from class com.rapidminer.operator.Operator

addError, addValue, addWarning, apply, checkDeprecations, checkForStop, checkIO, checkProperties, clearErrorList, cloneOperator, createExperimentTree, createExperimentTree, createFromXML, createMarkedExperimentTree, createMarkedProcessTree, createProcessTree, createProcessTree, getAddOnlyAdditionalOutput, getApplyCount, getDeliveredOutputClasses, getDeprecationInfo, getDesiredInputClasses, getEncoding, getErrorList, getExperiment, getInnerOperatorsXML, getInput, getInput, getInput, getInputDescription, getIOContainerForInApplyLoopBreakpoint, getIODescription, getLog, getName, getOperatorClassName, getOperatorDescription, getParameter, getParameterAsBoolean, getParameterAsColor, getParameterAsDouble, getParameterAsFile, getParameterAsFile, getParameterAsInputStream, getParameterAsInt, getParameterAsMatrix, getParameterAsString, getParameterList, getParameters, getParameterType, getParent, getProcess, getStartTime, getStatus, getUserDescription, getValue, getValues, getXML, hasBreakpoint, hasBreakpoint, hasInput, inApplyLoop, isDebugMode, isEnabled, isExpanded, isParallel, isParameterSet, log, logError, logNote, logWarning, performAdditionalChecks, processFinished, processStarts, register, registerOperator, remove, rename, resume, setApplyCount, setBreakpoint, setEnabled, setExpanded, setInput, setListParameter, setOperatorParameters, setParameter, setParameters, setParent, setUserDescription, toString, unregisterOperator, writeXML

Methods inherited from class java.lang.Object

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

Field Detail

PARAMETER_DATA_FILE

public static final java.lang.String PARAMETER_DATA_FILE

The parameter name for "The path to the data file."

See Also:

Constant Field Values

PARAMETER_LABEL_ATTRIBUTE

public static final java.lang.String PARAMETER_LABEL_ATTRIBUTE

The parameter name for "The (case sensitive) name of the label attribute"

See Also:

Constant Field Values

PARAMETER_ID_ATTRIBUTE

public static final java.lang.String PARAMETER_ID_ATTRIBUTE

The parameter name for "The (case sensitive) name of the id attribute"

See Also:

Constant Field Values

PARAMETER_WEIGHT_ATTRIBUTE

public static final java.lang.String PARAMETER_WEIGHT_ATTRIBUTE

The parameter name for "The (case sensitive) name of the weight attribute"

See Also:

Constant Field Values

PARAMETER_DATAMANAGEMENT

public static final java.lang.String PARAMETER_DATAMANAGEMENT

The parameter name for "Determines, how the data is represented internally."

See Also:

Constant Field Values

PARAMETER_DECIMAL_POINT_CHARACTER

public static final java.lang.String PARAMETER_DECIMAL_POINT_CHARACTER

The parameter name for "Character that is used as decimal point."

See Also:

Constant Field Values

PARAMETER_SAMPLE_RATIO

public static final java.lang.String PARAMETER_SAMPLE_RATIO

The parameter name for "The fraction of the data set which should be read (1 = all; only used if sample_size = -1)"

See Also:

Constant Field Values

PARAMETER_SAMPLE_SIZE

public static final java.lang.String PARAMETER_SAMPLE_SIZE

The parameter name for "The exact number of samples which should be read (-1 = use sample ratio; if not -1, sample_ratio will not have any effect)"

See Also:

Constant Field Values

PARAMETER_LOCAL_RANDOM_SEED

public static final java.lang.String PARAMETER_LOCAL_RANDOM_SEED

The parameter name for "Use the given random seed instead of global random numbers (only for permutation, -1: use global)."

See Also:

Constant Field Values

Constructor Detail

ArffExampleSource

public ArffExampleSource(OperatorDescription description)

Method Detail

createExampleSet

public ExampleSet createExampleSet()
                            throws OperatorException

Description copied from class: AbstractExampleSource

Creates (or reads) the ExampleSet that will be returned by AbstractReader.apply().

Specified by:

createExampleSet in class AbstractExampleSource

Throws:

OperatorException

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.

Specified by:

getParameterTypes in interface ParameterHandler

Overrides:

getParameterTypes in class Operator