instances.html

< 数据挖掘--实用机器学习技术及java实现> 一书结合数据挖掘和机器学习的知识,作者陈述了自动挖掘模式的基础理论,并且以java语言实现了具有代表性的各类数据挖掘方法.例如:class

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<A NAME="checkInstance(weka.core.Instance)"><!-- --></A><H3>
checkInstance</H3>
<PRE>
public final boolean <B>checkInstance</B>(<A HREF="../../weka/core/Instance.html">Instance</A>&nbsp;instance)</PRE>
<DL>
<DD>Checks if the given instance is compatible
 with this dataset. Only looks at the size of
 the instance and the ranges of the values for 
 nominal and string attributes.<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Returns:</B><DD>true if the instance is compatible with the dataset</DL>
</DD>
</DL>
<HR>

<A NAME="classAttribute()"><!-- --></A><H3>
classAttribute</H3>
<PRE>
public final <A HREF="../../weka/core/Attribute.html">Attribute</A> <B>classAttribute</B>()</PRE>
<DL>
<DD>Returns the class attribute.<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Returns:</B><DD>the class attribute<DT><B>Throws:</B><DD><CODE><A HREF="../../weka/core/UnassignedClassException.html">UnassignedClassException</A></CODE> - if the class is not set</DL>
</DD>
</DL>
<HR>

<A NAME="classIndex()"><!-- --></A><H3>
classIndex</H3>
<PRE>
public final int <B>classIndex</B>()</PRE>
<DL>
<DD>Returns the class attribute's index. Returns negative number
 if it's undefined.<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Returns:</B><DD>the class index as an integer</DL>
</DD>
</DL>
<HR>

<A NAME="compactify()"><!-- --></A><H3>
compactify</H3>
<PRE>
public final void <B>compactify</B>()</PRE>
<DL>
<DD>Compactifies the set of instances. Decreases the capacity of
 the set so that it matches the number of instances in the set.<DD><DL>
</DL>
</DD>
</DL>
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<A NAME="delete()"><!-- --></A><H3>
delete</H3>
<PRE>
public final void <B>delete</B>()</PRE>
<DL>
<DD>Removes all instances from the set.<DD><DL>
</DL>
</DD>
</DL>
<HR>

<A NAME="delete(int)"><!-- --></A><H3>
delete</H3>
<PRE>
public final void <B>delete</B>(int&nbsp;index)</PRE>
<DL>
<DD>Removes an instance at the given position from the set.<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>index</CODE> - the instance's position</DL>
</DD>
</DL>
<HR>

<A NAME="deleteAttributeAt(int)"><!-- --></A><H3>
deleteAttributeAt</H3>
<PRE>
public void <B>deleteAttributeAt</B>(int&nbsp;position)</PRE>
<DL>
<DD>Deletes an attribute at the given position 
 (0 to numAttributes() - 1). A deep copy of the attribute
 information is performed before the attribute is deleted.<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>pos</CODE> - the attribute's position<DT><B>Throws:</B><DD><CODE>java.lang.IllegalArgumentException</CODE> - if the given index is out of range or the
 class attribute is being deleted</DL>
</DD>
</DL>
<HR>

<A NAME="deleteStringAttributes()"><!-- --></A><H3>
deleteStringAttributes</H3>
<PRE>
public void <B>deleteStringAttributes</B>()</PRE>
<DL>
<DD>Deletes all string attributes in the dataset. A deep copy of the attribute
 information is performed before an attribute is deleted.<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Throws:</B><DD><CODE>java.lang.IllegalArgumentException</CODE> - if string attribute couldn't be 
 successfully deleted (probably because it is the class attribute).</DL>
</DD>
</DL>
<HR>

<A NAME="deleteWithMissing(int)"><!-- --></A><H3>
deleteWithMissing</H3>
<PRE>
public final void <B>deleteWithMissing</B>(int&nbsp;attIndex)</PRE>
<DL>
<DD>Removes all instances with missing values for a particular
 attribute from the dataset.<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>attIndex</CODE> - the attribute's index</DL>
</DD>
</DL>
<HR>

<A NAME="deleteWithMissing(weka.core.Attribute)"><!-- --></A><H3>
deleteWithMissing</H3>
<PRE>
public final void <B>deleteWithMissing</B>(<A HREF="../../weka/core/Attribute.html">Attribute</A>&nbsp;att)</PRE>
<DL>
<DD>Removes all instances with missing values for a particular
 attribute from the dataset.<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>att</CODE> - the attribute</DL>
</DD>
</DL>
<HR>

<A NAME="deleteWithMissingClass()"><!-- --></A><H3>
deleteWithMissingClass</H3>
<PRE>
public final void <B>deleteWithMissingClass</B>()</PRE>
<DL>
<DD>Removes all instances with a missing class value
 from the dataset.<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Throws:</B><DD><CODE><A HREF="../../weka/core/UnassignedClassException.html">UnassignedClassException</A></CODE> - if class is not set</DL>
</DD>
</DL>
<HR>

<A NAME="enumerateAttributes()"><!-- --></A><H3>
enumerateAttributes</H3>
<PRE>
public java.util.Enumeration <B>enumerateAttributes</B>()</PRE>
<DL>
<DD>Returns an enumeration of all the attributes.<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Returns:</B><DD>enumeration of all the attributes.</DL>
</DD>
</DL>
<HR>

<A NAME="enumerateInstances()"><!-- --></A><H3>
enumerateInstances</H3>
<PRE>
public final java.util.Enumeration <B>enumerateInstances</B>()</PRE>
<DL>
<DD>Returns an enumeration of all instances in the dataset.<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Returns:</B><DD>enumeration of all instances in the dataset</DL>
</DD>
</DL>
<HR>

<A NAME="equalHeaders(weka.core.Instances)"><!-- --></A><H3>
equalHeaders</H3>
<PRE>
public final boolean <B>equalHeaders</B>(<A HREF="../../weka/core/Instances.html">Instances</A>&nbsp;dataset)</PRE>
<DL>
<DD>Checks if two headers are equivalent.<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>dataset</CODE> - another dataset<DT><B>Returns:</B><DD>true if the header of the given dataset is equivalent 
 to this header</DL>
</DD>
</DL>
<HR>

<A NAME="firstInstance()"><!-- --></A><H3>
firstInstance</H3>
<PRE>
public final <A HREF="../../weka/core/Instance.html">Instance</A> <B>firstInstance</B>()</PRE>
<DL>
<DD>Returns the first instance in the set.<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Returns:</B><DD>the first instance in the set</DL>
</DD>
</DL>
<HR>

<A NAME="insertAttributeAt(weka.core.Attribute, int)"><!-- --></A><H3>
insertAttributeAt</H3>
<PRE>
public void <B>insertAttributeAt</B>(<A HREF="../../weka/core/Attribute.html">Attribute</A>&nbsp;att,
                              int&nbsp;position)</PRE>
<DL>
<DD>Inserts an attribute at the given position (0 to 
 numAttributes()) and sets all values to be missing.
 Shallow copies the attribute before it is inserted, and performs
 a deep copy of the existing attribute information.<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>att</CODE> - the attribute to be inserted<DD><CODE>pos</CODE> - the attribute's position<DT><B>Throws:</B><DD><CODE>java.lang.IllegalArgumentException</CODE> - if the given index is out of range</DL>
</DD>
</DL>
<HR>

<A NAME="instance(int)"><!-- --></A><H3>
instance</H3>
<PRE>
public final <A HREF="../../weka/core/Instance.html">Instance</A> <B>instance</B>(int&nbsp;index)</PRE>
<DL>
<DD>Returns the instance at the given position.<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>index</CODE> - the instance's index<DT><B>Returns:</B><DD>the instance at the given position</DL>
</DD>
</DL>
<HR>

<A NAME="lastInstance()"><!-- --></A><H3>
lastInstance</H3>
<PRE>
public final <A HREF="../../weka/core/Instance.html">Instance</A> <B>lastInstance</B>()</PRE>
<DL>
<DD>Returns the last instance in the set.<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Returns:</B><DD>the last instance in the set</DL>
</DD>
</DL>
<HR>

<A NAME="meanOrMode(int)"><!-- --></A><H3>
meanOrMode</H3>
<PRE>
public final double <B>meanOrMode</B>(int&nbsp;attIndex)</PRE>
<DL>
<DD>Returns the mean (mode) for a numeric (nominal) attribute as
 a floating-point value. Returns 0 if the attribute is neither nominal nor 
 numeric. If all values are missing it returns zero.<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>attIndex</CODE> - the attribute's index<DT><B>Returns:</B><DD>the mean or the mode</DL>
</DD>
</DL>
<HR>

<A NAME="meanOrMode(weka.core.Attribute)"><!-- --></A><H3>
meanOrMode</H3>
<PRE>
public final double <B>meanOrMode</B>(<A HREF="../../weka/core/Attribute.html">Attribute</A>&nbsp;att)</PRE>
<DL>
<DD>Returns the mean (mode) for a numeric (nominal) attribute as a
 floating-point value.  Returns 0 if the attribute is neither
 nominal nor numeric.  If all values are missing it returns zero.<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>att</CODE> - the attribute<DT><B>Returns:</B><DD>the mean or the mode</DL>
</DD>
</DL>
<HR>

<A NAME="numAttributes()"><!-- --></A><H3>
numAttributes</H3>
<PRE>
public final int <B>numAttributes</B>()</PRE>
<DL>
<DD>Returns the number of attributes.<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Returns:</B><DD>the number of attributes as an integer</DL>
</DD>
</DL>
<HR>

<A NAME="numClasses()"><!-- --></A><H3>
numClasses</H3>
<PRE>
public final int <B>numClasses</B>()</PRE>
<DL>
<DD>Returns the number of class labels.<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Returns:</B><DD>the number of class labels as an integer if the class 
 attribute is nominal, 1 otherwise.<DT><B>Throws:</B><DD><CODE><A HREF="../../weka/core/UnassignedClassException.html">UnassignedClassException</A></CODE> - if the class is not set</DL>
</DD>
</DL>
<HR>

<A NAME="numDistinctValues(int)"><!-- --></A><H3>
numDistinctValues</H3>
<PRE>
public final int <B>numDistinctValues</B>(int&nbsp;attIndex)</PRE>
<DL>
<DD>Returns the number of distinct values of a given attribute.
 Returns the number of instances if the attribute is a
 string attribute. The value 'missing' is not counted.<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>attIndex</CODE> - the attribute<DT><B>Returns:</B><DD>the number of distinct values of a given attribute</DL>
</DD>
</DL>
<HR>