costmatrix.html

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        java.lang.Object&nbsp;value)</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Set the value of a particular cell in the matrix</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;void</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../weka/classifiers/CostMatrix.html#setElement(int, int, double)">setElement</A></B>(int&nbsp;rowIndex,
           int&nbsp;columnIndex,
           double&nbsp;value)</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Set the value of a cell as a double</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;int</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../weka/classifiers/CostMatrix.html#size()">size</A></B>()</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The number of rows (and columns)</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;java.lang.String</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../weka/classifiers/CostMatrix.html#toMatlab()">toMatlab</A></B>()</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;converts the Matrix into a single line Matlab string: matrix is enclosed 
 by parentheses, rows are separated by semicolon and single cells by
 blanks, e.g., [1 2; 3 4].</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;java.lang.String</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../weka/classifiers/CostMatrix.html#toString()">toString</A></B>()</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Converts a matrix to a string.</TD>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE>&nbsp;void</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../weka/classifiers/CostMatrix.html#write(java.io.Writer)">write</A></B>(java.io.Writer&nbsp;w)</CODE>

<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Writes out a matrix.</TD>
</TR>
</TABLE>
&nbsp;<A NAME="methods_inherited_from_class_java.lang.Object"><!-- --></A>
<TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY="">
<TR BGCOLOR="#EEEEFF" CLASS="TableSubHeadingColor">
<TH ALIGN="left"><B>Methods inherited from class java.lang.Object</B></TH>
</TR>
<TR BGCOLOR="white" CLASS="TableRowColor">
<TD><CODE>equals, getClass, hashCode, notify, notifyAll, wait, wait, wait</CODE></TD>
</TR>
</TABLE>
&nbsp;
<P>

<!-- ============ FIELD DETAIL =========== -->

<A NAME="field_detail"><!-- --></A>
<TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY="">
<TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor">
<TH ALIGN="left" COLSPAN="1"><FONT SIZE="+2">
<B>Field Detail</B></FONT></TH>
</TR>
</TABLE>

<A NAME="FILE_EXTENSION"><!-- --></A><H3>
FILE_EXTENSION</H3>
<PRE>
public static java.lang.String <B>FILE_EXTENSION</B></PRE>
<DL>
<DD>The deafult file extension for cost matrix files
<P>
<DL>
</DL>
</DL>

<!-- ========= CONSTRUCTOR DETAIL ======== -->

<A NAME="constructor_detail"><!-- --></A>
<TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY="">
<TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor">
<TH ALIGN="left" COLSPAN="1"><FONT SIZE="+2">
<B>Constructor Detail</B></FONT></TH>
</TR>
</TABLE>

<A NAME="CostMatrix(int)"><!-- --></A><H3>
CostMatrix</H3>
<PRE>
public <B>CostMatrix</B>(int&nbsp;numOfClasses)</PRE>
<DL>
<DD>Creates a default cost matrix of a particular size. 
 All diagonal values will be 0 and all non-diagonal values 1.
<P>
<DL>
<DT><B>Parameters:</B><DD><CODE>numOfClasses</CODE> - the number of classes that the cost matrix holds.</DL>
</DL>
<HR>

<A NAME="CostMatrix(weka.classifiers.CostMatrix)"><!-- --></A><H3>
CostMatrix</H3>
<PRE>
public <B>CostMatrix</B>(<A HREF="../../weka/classifiers/CostMatrix.html" title="class in weka.classifiers">CostMatrix</A>&nbsp;toCopy)</PRE>
<DL>
<DD>Creates a cost matrix that is a copy of another.
<P>
<DL>
<DT><B>Parameters:</B><DD><CODE>toCopy</CODE> - the matrix to copy.</DL>
</DL>
<HR>

<A NAME="CostMatrix(java.io.Reader)"><!-- --></A><H3>
CostMatrix</H3>
<PRE>
public <B>CostMatrix</B>(java.io.Reader&nbsp;reader)
           throws java.lang.Exception</PRE>
<DL>
<DD>Reads a matrix from a reader. The first line in the file should
 contain the number of rows and columns. Subsequent lines
 contain elements of the matrix. 
 (FracPete: taken from old weka.core.Matrix class)
<P>
<DL>
<DT><B>Parameters:</B><DD><CODE>reader</CODE> - the reader containing the matrix
<DT><B>Throws:</B>
<DD><CODE>java.lang.Exception</CODE> - if an error occurs<DT><B>See Also:</B><DD><A HREF="../../weka/classifiers/CostMatrix.html#write(java.io.Writer)"><CODE>write(Writer)</CODE></A></DL>
</DL>

<!-- ============ METHOD DETAIL ========== -->

<A NAME="method_detail"><!-- --></A>
<TABLE BORDER="1" WIDTH="100%" CELLPADDING="3" CELLSPACING="0" SUMMARY="">
<TR BGCOLOR="#CCCCFF" CLASS="TableHeadingColor">
<TH ALIGN="left" COLSPAN="1"><FONT SIZE="+2">
<B>Method Detail</B></FONT></TH>
</TR>
</TABLE>

<A NAME="initialize()"><!-- --></A><H3>
initialize</H3>
<PRE>
public void <B>initialize</B>()</PRE>
<DL>
<DD>Initializes the matrix
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>
</DL>
</DD>
</DL>
<HR>

<A NAME="size()"><!-- --></A><H3>
size</H3>
<PRE>
public int <B>size</B>()</PRE>
<DL>
<DD>The number of rows (and columns)
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>

<DT><B>Returns:</B><DD>the size of the matrix</DL>
</DD>
</DL>
<HR>

<A NAME="numColumns()"><!-- --></A><H3>
numColumns</H3>
<PRE>
public int <B>numColumns</B>()</PRE>
<DL>
<DD>Same as size
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>

<DT><B>Returns:</B><DD>the number of columns</DL>
</DD>
</DL>
<HR>

<A NAME="numRows()"><!-- --></A><H3>
numRows</H3>
<PRE>
public int <B>numRows</B>()</PRE>
<DL>
<DD>Same as size
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>

<DT><B>Returns:</B><DD>the number of rows</DL>
</DD>
</DL>
<HR>

<A NAME="applyCostMatrix(weka.core.Instances, java.util.Random)"><!-- --></A><H3>
applyCostMatrix</H3>
<PRE>
public <A HREF="../../weka/core/Instances.html" title="class in weka.core">Instances</A> <B>applyCostMatrix</B>(<A HREF="../../weka/core/Instances.html" title="class in weka.core">Instances</A>&nbsp;data,
                                 java.util.Random&nbsp;random)
                          throws java.lang.Exception</PRE>
<DL>
<DD>Applies the cost matrix to a set of instances. If a random number generator is 
 supplied the instances will be resampled, otherwise they will be rewighted. 
 Adapted from code once sitting in Instances.java
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>data</CODE> - the instances to reweight.<DD><CODE>random</CODE> - a random number generator for resampling, if null then instances are
 rewighted.
<DT><B>Returns:</B><DD>a new dataset reflecting the cost of misclassification.
<DT><B>Throws:</B>
<DD><CODE>java.lang.Exception</CODE> - if the data has no class or the matrix in inappropriate.</DL>
</DD>
</DL>
<HR>

<A NAME="expectedCosts(double[])"><!-- --></A><H3>
expectedCosts</H3>
<PRE>
public double[] <B>expectedCosts</B>(double[]&nbsp;classProbs)
                       throws java.lang.Exception</PRE>
<DL>
<DD>Calculates the expected misclassification cost for each possible class value,
 given class probability estimates.
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>classProbs</CODE> - the class probability estimates.
<DT><B>Returns:</B><DD>the expected costs.
<DT><B>Throws:</B>
<DD><CODE>java.lang.Exception</CODE> - if the wrong number of class probabilities is supplied.</DL>
</DD>
</DL>
<HR>

<A NAME="expectedCosts(double[], weka.core.Instance)"><!-- --></A><H3>
expectedCosts</H3>
<PRE>
public double[] <B>expectedCosts</B>(double[]&nbsp;classProbs,
                              <A HREF="../../weka/core/Instance.html" title="class in weka.core">Instance</A>&nbsp;inst)
                       throws java.lang.Exception</PRE>
<DL>
<DD>Calculates the expected misclassification cost for each possible class value,
 given class probability estimates.
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>classProbs</CODE> - the class probability estimates.<DD><CODE>inst</CODE> - the current instance for which the class probabilites
 apply. Is used for computing any non-fixed cost values.
<DT><B>Returns:</B><DD>the expected costs.
<DT><B>Throws:</B>
<DD><CODE>java.lang.Exception</CODE> - if something goes wrong</DL>
</DD>
</DL>
<HR>

<A NAME="getMaxCost(int)"><!-- --></A><H3>
getMaxCost</H3>
<PRE>
public double <B>getMaxCost</B>(int&nbsp;classVal)
                  throws java.lang.Exception</PRE>
<DL>
<DD>Gets the maximum cost for a particular class value.
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>classVal</CODE> - the class value.
<DT><B>Returns:</B><DD>the maximum cost.
<DT><B>Throws:</B>
<DD><CODE>java.lang.Exception</CODE> - if cost matrix contains non-fixed
 costs</DL>
</DD>
</DL>
<HR>