All Packages Class Hierarchy This Package Previous Next Index WEKA's home
Class weka.classifiers.evaluation.ConfusionMatrix
java.lang.Object
|
+----weka.core.Matrix
|
+----weka.classifiers.evaluation.ConfusionMatrix
- public class ConfusionMatrix
- extends Matrix
Cells of this matrix correspond to counts of the number (or weight)
of predictions for each actual value / predicted value combination.
- Author:
- Len Trigg (len@intelligenesis.net)
-
ConfusionMatrix(String[])
- Creates the confusion matrix with the given class names.
-
addPrediction(NominalPrediction)
- Includes a prediction in the confusion matrix.
-
addPredictions(FastVector)
- Includes a whole bunch of predictions in the confusion matrix.
-
className(int)
- Gets the name of one of the classes.
-
clone()
- Creates and returns a clone of this object.
-
correct()
- Gets the number of correct classifications (that is, for which a
correct prediction was made).
-
errorRate()
- Returns the estimated error rate.
-
getTwoClassStats(int)
- Gets the performance with respect to one of the classes
as a TwoClassStats object.
-
incorrect()
- Gets the number of incorrect classifications (that is, for which an
incorrect prediction was made).
-
makeWeighted(CostMatrix)
- Makes a copy of this ConfusionMatrix after applying the
supplied CostMatrix to the cells.
-
size()
- Gets the number of classes.
-
toString()
- Calls toString() with a default title.
-
toString(String)
- Outputs the performance statistics as a classification confusion
matrix.
-
total()
- Gets the number of predictions that were made
(actually the sum of the weights of predictions where the
class value was known).
ConfusionMatrix
public ConfusionMatrix(String classNames[])
- Creates the confusion matrix with the given class names.
- Parameters:
- classNames - an array containing the names the classes.
makeWeighted
public ConfusionMatrix makeWeighted(CostMatrix costs) throws Exception
- Makes a copy of this ConfusionMatrix after applying the
supplied CostMatrix to the cells. The resulting ConfusionMatrix
can be used to get cost-weighted statistics.
- Parameters:
- costs - the CostMatrix.
- Returns:
- a ConfusionMatrix that has had costs applied.
- Throws: Exception
- if the CostMatrix is not of the same size
as this ConfusionMatrix.
clone
public Object clone() throws CloneNotSupportedException
- Creates and returns a clone of this object.
- Returns:
- a clone of this instance.
- Throws: CloneNotSupportedException
- if an error occurs
- Overrides:
- clone in class Matrix
size
public int size()
- Gets the number of classes.
- Returns:
- the number of classes
className
public String className(int index)
- Gets the name of one of the classes.
- Parameters:
- index - the index of the class.
- Returns:
- the class name.
addPrediction
public void addPrediction(NominalPrediction pred) throws Exception
- Includes a prediction in the confusion matrix.
- Parameters:
- pred - the NominalPrediction to include
- Throws: Exception
- if no valid prediction was made (i.e.
unclassified).
addPredictions
public void addPredictions(FastVector predictions) throws Exception
- Includes a whole bunch of predictions in the confusion matrix.
- Parameters:
- predictions - a FastVector containing the NominalPredictions
to include
- Throws: Exception
- if no valid prediction was made (i.e.
unclassified).
getTwoClassStats
public TwoClassStats getTwoClassStats(int classIndex)
- Gets the performance with respect to one of the classes
as a TwoClassStats object.
- Parameters:
- classIndex - the index of the class of interest.
- Returns:
- the generated TwoClassStats object.
correct
public double correct()
- Gets the number of correct classifications (that is, for which a
correct prediction was made). (Actually the sum of the weights of
these classifications)
- Returns:
- the number of correct classifications
incorrect
public double incorrect()
- Gets the number of incorrect classifications (that is, for which an
incorrect prediction was made). (Actually the sum of the weights of
these classifications)
- Returns:
- the number of incorrect classifications
total
public double total()
- Gets the number of predictions that were made
(actually the sum of the weights of predictions where the
class value was known).
- Returns:
- the number of predictions with known class
errorRate
public double errorRate()
- Returns the estimated error rate.
- Returns:
- the estimated error rate (between 0 and 1).
toString
public String toString()
- Calls toString() with a default title.
- Returns:
- the confusion matrix as a string
- Overrides:
- toString in class Matrix
toString
public String toString(String title)
- Outputs the performance statistics as a classification confusion
matrix. For each class value, shows the distribution of
predicted class values.
- Parameters:
- title - the title for the confusion matrix
- Returns:
- the confusion matrix as a String
All Packages Class Hierarchy This Package Previous Next Index WEKA's home