Tree (JMSL Numerical Library (jmsl) 2021.0.0 API)

java.lang.Object
- com.imsl.datamining.decisionTree.Tree

All Implemented Interfaces:

Serializable, Cloneable
```
public class Tree
extends Object
implements Serializable, Cloneable
```
Serves as the root node of a decision tree and contains information about the relationship of child nodes.

See Also:

Serialized Form

Constructor Summary

Constructors
Constructor and Description
`Tree(int nRows, int minObsAllowedInChild, int maxNumberOfCategories, int maxNumberOfNodes, int nClasses, int nPreds, PredictiveModel.VariableType varType, int[] predNValues, PredictiveModel.VariableType[] predType, int nyMissing)` Creates the root node of a decision tree and contains information about the relationship of child nodes.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`protected Tree`	`clone()` Returns a clone of this object.
`TreeNode`	`getNode(int i)` Returns a copy of the specified node of the decision tree.
`TreeNode[]`	`getNodes()` Returns nodes within a decision tree.
`int`	`getNumberOfClasses()` Returns the number of classes assumed by the response variable, if the response variable is categorical.
`int`	`getNumberOfLevels()` Returns the number of levels or depth of a tree.
`int`	`getNumberOfNodes()` Returns the number of nodes (size of a tree).
`int`	`getNumberOfPredictors()` Returns the number of predictors used in the model.
`int`	`getNumberOfSurrogateSplits()` Returns the number of surrogate splits searched for at each tree node.
`int[]`	`getPredictorNumberOfValues()` Returns the number of distinct values of each predictor variable.
`PredictiveModel.VariableType`	`getPredictorType(int i)` Returns the `PredictiveModel.VariableType` of a predictor variable.
`PredictiveModel.VariableType`	`getResponseType()` Returns the `PredictiveModel.VariableType` of the response variable.
`boolean[]`	`getTerminalNodeIndicators()` Returns the terminal node indicator array.
`boolean`	`isTerminalNode(int i)` Returns the terminal node indicator of the node at the given index.

Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - Tree
```
public Tree(int nRows,
            int minObsAllowedInChild,
            int maxNumberOfCategories,
            int maxNumberOfNodes,
            int nClasses,
            int nPreds,
            PredictiveModel.VariableType varType,
            int[] predNValues,
            PredictiveModel.VariableType[] predType,
            int nyMissing)
```
    Creates the root node of a decision tree and contains information about the relationship of child nodes.
    
    Parameters:
    
    nRows - an int, the number of observations (rows) in the input data
    
    minObsAllowedInChild - an int, the number of observations necessary in all potential child nodes before a node may be split
    
    maxNumberOfCategories - an int, the maximum number of categories allowed for categorical predictor variables
    
    maxNumberOfNodes - an int, the maximum number of nodes allowed in the tree
    
    nClasses - an int, the number of classes assumed by the response variable, if the response variable is categorical
    
    nPreds - an int, the number of predictors used in the model
    
    varType - a PredictiveModel.VariableType array of length equal to the number of variables active in the model, which is less than or equal to the available columns in the data, (xy[i].length)
    
    predNValues - an int array containing the number of values of each predictor variable
    
    predType - a PredictiveModel.VariableType array of length equal to the number of predictors containing the type of each predictor variable
    
    nyMissing - an int equal to the number of missing values in the response variable
- Method Detail
  - getNode
```
public TreeNode getNode(int i)
```
    Returns a copy of the specified node of the decision tree.
    
    Parameters:
    
    i - an int that specifies the index of a TreeNode to be returned
    
    Returns:
    
    a TreeNode corresponding to the specified index
  - getTerminalNodeIndicators
```
public boolean[] getTerminalNodeIndicators()
```
    Returns the terminal node indicator array.
    
    Returns:
    
    a boolean array indicating which nodes are terminal nodes and which are not. If true at index i, then the node at index i is a terminal node.
  - getNodes
```
public TreeNode[] getNodes()
```
    Returns nodes within a decision tree.
    
    Returns:
    
    a TreeNode array containing a copy of the TreeNodes within the decision tree
  - getNumberOfClasses
```
public int getNumberOfClasses()
```
    Returns the number of classes assumed by the response variable, if the response variable is categorical.
    
    Returns:
    
    an int, the number of classes assumed by the response variable, if the response variable is categorical
  - getNumberOfLevels
```
public int getNumberOfLevels()
```
    Returns the number of levels or depth of a tree.
    
    Returns:
    
    an int specifying the number of levels or depth of a tree
  - getNumberOfNodes
```
public int getNumberOfNodes()
```
    Returns the number of nodes (size of a tree).
    
    Returns:
    
    an int, the number of nodes or size of the tree
  - getNumberOfPredictors
```
public int getNumberOfPredictors()
```
    Returns the number of predictors used in the model.
    
    Returns:
    
    an int, the number of predictors used in the model
  - getNumberOfSurrogateSplits
```
public int getNumberOfSurrogateSplits()
```
    Returns the number of surrogate splits searched for at each tree node.
    Surrogate splits are relevant only for classes that implement the com.imsl.datamining.decisionTree.DecisionTreeSurrogateMethod interface.
    
    Returns:
    
    an int, the number of surrogate splits searched for at each node
  - getPredictorNumberOfValues
```
public int[] getPredictorNumberOfValues()
```
    Returns the number of distinct values of each predictor variable.
    For continuous predictor variables, the value is set to 0 and is not meaningful.
    
    Returns:
    
    an int array containing the number of values of each predictor variable
  - getPredictorType
```
public PredictiveModel.VariableType getPredictorType(int i)
```
    Returns the PredictiveModel.VariableType of a predictor variable.
    
    Parameters:
    
    i - an int, the index of the predictor
    
    Returns:
    
    a VariableType, the variable type of the predictor at index i
  - getResponseType
```
public PredictiveModel.VariableType getResponseType()
```
    Returns the PredictiveModel.VariableType of the response variable.
    
    Returns:
    
    a PredictiveModel.VariableType, indicates the response variable type
  - isTerminalNode
```
public boolean isTerminalNode(int i)
```
    Returns the terminal node indicator of the node at the given index.
    
    Parameters:
    
    i - an int specifying the index of the node
    
    Returns:
    
    a boolean, that if true, then the node at index i is a terminal node
  - clone
```
protected Tree clone()
```
    Returns a clone of this object.
    
    Overrides:
    
    clone in class Object
    
    Returns:
    
    a Tree that is a copy of this object

Class Tree

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Tree

Method Detail

getNode

getTerminalNodeIndicators

getNodes

getNumberOfClasses

getNumberOfLevels

getNumberOfNodes

getNumberOfPredictors

getNumberOfSurrogateSplits

getPredictorNumberOfValues

getPredictorType

getResponseType

isTerminalNode

clone