jsat.classifiers.trees

Enum TreePruner.PruningMethod

java.lang.Object

java.lang.Enum<TreePruner.PruningMethod>

jsat.classifiers.trees.TreePruner.PruningMethod

All Implemented Interfaces:

Serializable, Comparable<TreePruner.PruningMethod>

Enclosing class:

TreePruner

public static enum TreePruner.PruningMethod
extends Enum<TreePruner.PruningMethod>

The method of pruning to use

Enum Constant Summary

Enum Constants

Enum Constant and Description
ERROR_BASED Bottom-Up pessimistic pruning using Error based Pruning from the C4.5 algorithm.
NONE The tree will be left as generated, no pruning will occur.
REDUCED_ERROR The tree will be pruned in a bottom up fashion, removing leaf nodes if the removal does not reduce the accuracy on the testing set

Method Summary

Modifier and Type	Method and Description
static TreePruner.PruningMethod	valueOf(String name) Returns the enum constant of this type with the specified name.
static TreePruner.PruningMethod[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

NONE

public static final TreePruner.PruningMethod NONE

The tree will be left as generated, no pruning will occur.

REDUCED_ERROR

public static final TreePruner.PruningMethod REDUCED_ERROR

The tree will be pruned in a bottom up fashion, removing leaf nodes if the removal does not reduce the accuracy on the testing set

ERROR_BASED

public static final TreePruner.PruningMethod ERROR_BASED

Bottom-Up pessimistic pruning using Error based Pruning from the C4.5 algorithm. If the node visitor supports TreeNodeVisitor.setPath(int, jsat.classifiers.trees.TreeNodeVisitor) it will perform sub tree replacement for the maximal sub tree.
The default Confidence (CF) is 0.25, as used in the C4.5 algorithm.

NOTE: For the one case where the root would be pruned by taking the sub tree with the most nodes, this implementation will not perform that step. However, this is incredibly rare - and otherwise performs the same.

Method Detail

values

public static TreePruner.PruningMethod[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (TreePruner.PruningMethod c : TreePruner.PruningMethod.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static TreePruner.PruningMethod valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null