weka.estimators
Class EstimatorUtils

java.lang.Object
  extended by weka.estimators.EstimatorUtils
All Implemented Interfaces:
RevisionHandler

public class EstimatorUtils
extends java.lang.Object
implements RevisionHandler

Contains static utility functions for Estimators.

Version:
$Revision: 1.4 $
Author:
Gabi Schmidberger (gabi@cs.waikato.ac.nz)

Constructor Summary
EstimatorUtils()
           
 
Method Summary
static java.lang.String cutpointsToString(double[] cutPoints, boolean[] cutAndLeft)
          Returns a string representing the cutpoints
static double findMinDistance(Instances inst, int attrIndex)
          Find the minimum distance between values
static Instances getInstancesFromClass(Instances data, int classIndex, double classValue)
          Returns a dataset that contains of all instances of a certain class value.
static java.util.Vector getInstancesFromClass(Instances data, int attrIndex, int classIndex, double classValue, Instances workData)
          Returns a dataset that contains all instances of a certain class value.
static Instances getInstancesFromValue(Instances data, int index, double v)
          Returns a dataset that contains of all instances of a certain value for the given attribute.
static int getMinMax(Instances inst, int attrIndex, double[] minMax)
          Find the minimum and the maximum of the attribute and return it in the last parameter..
 java.lang.String getRevision()
          Returns the revision string.
static void writeCurve(java.lang.String f, Estimator est, double min, double max, int numPoints)
          Output of an n points of a density curve.
static void writeCurve(java.lang.String f, Estimator est, Estimator classEst, double classIndex, double min, double max, int numPoints)
          Output of an n points of a density curve.
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

EstimatorUtils

public EstimatorUtils()
Method Detail

findMinDistance

public static double findMinDistance(Instances inst,
                                     int attrIndex)
Find the minimum distance between values

Parameters:
inst - sorted instances, sorted
attrIndex - index of the attribute, they are sorted after
Returns:
the minimal distance

getMinMax

public static int getMinMax(Instances inst,
                            int attrIndex,
                            double[] minMax)
                     throws java.lang.Exception
Find the minimum and the maximum of the attribute and return it in the last parameter..

Parameters:
inst - instances used to build the estimator
attrIndex - index of the attribute
minMax - the array to return minimum and maximum in
Returns:
number of not missing values
Throws:
java.lang.Exception - if parameter minMax wasn't initialized properly

getInstancesFromClass

public static java.util.Vector getInstancesFromClass(Instances data,
                                                     int attrIndex,
                                                     int classIndex,
                                                     double classValue,
                                                     Instances workData)
Returns a dataset that contains all instances of a certain class value.

Parameters:
data - dataset to select the instances from
attrIndex - index of the relevant attribute
classIndex - index of the class attribute
classValue - the relevant class value
Returns:
a dataset with only

getInstancesFromClass

public static Instances getInstancesFromClass(Instances data,
                                              int classIndex,
                                              double classValue)
Returns a dataset that contains of all instances of a certain class value.

Parameters:
data - dataset to select the instances from
classIndex - index of the class attribute
classValue - the class value
Returns:
a dataset with only instances of one class value

writeCurve

public static void writeCurve(java.lang.String f,
                              Estimator est,
                              double min,
                              double max,
                              int numPoints)
                       throws java.lang.Exception
Output of an n points of a density curve. Filename is parameter f + ".curv".

Parameters:
f - string to build filename
est -
min -
max -
numPoints -
Throws:
java.lang.Exception - if something goes wrong

writeCurve

public static void writeCurve(java.lang.String f,
                              Estimator est,
                              Estimator classEst,
                              double classIndex,
                              double min,
                              double max,
                              int numPoints)
                       throws java.lang.Exception
Output of an n points of a density curve. Filename is parameter f + ".curv".

Parameters:
f - string to build filename
est -
classEst -
classIndex -
min -
max -
numPoints -
Throws:
java.lang.Exception - if something goes wrong

getInstancesFromValue

public static Instances getInstancesFromValue(Instances data,
                                              int index,
                                              double v)
Returns a dataset that contains of all instances of a certain value for the given attribute.

Parameters:
data - dataset to select the instances from
index - the index of the attribute
v - the value
Returns:
a subdataset with only instances of one value for the attribute

cutpointsToString

public static java.lang.String cutpointsToString(double[] cutPoints,
                                                 boolean[] cutAndLeft)
Returns a string representing the cutpoints


getRevision

public java.lang.String getRevision()
Returns the revision string.

Specified by:
getRevision in interface RevisionHandler
Returns:
the revision