Source Code for Module rdkit.ML.DecTree.QuantTree

 1  # $Id: QuantTree.py 997 2009-02-25 06:12:43Z glandrum $ 
 2  # 
 3  #  Copyright (C) 2001, 2003  greg Landrum and Rational Discovery LLC 
 4  #   All Rights Reserved 
 5  # 
 6  """ Defines the class _QuantTreeNode_, used to represent decision trees with automatic 
 7   quantization bounds 
 8   
 9    _QuantTreeNode_ is derived from _DecTree.DecTreeNode_ 
10   
11  """ 
12  from rdkit.ML.DecTree import DecTree,Tree 
13   
14 -class QuantTreeNode(DecTree.DecTreeNode): 
15    """  
16      
17    """ 
18 -  def __init__(self,*args,**kwargs): 
19      apply(DecTree.DecTreeNode.__init__,(self,)+args,kwargs) 
20      self.qBounds = [] 
21      self.nBounds = 0 
22 -  def ClassifyExample(self,example,appendExamples=0): 
23      """ Recursively classify an example by running it through the tree 
24       
25        **Arguments** 
26   
27          - example: the example to be classified 
28   
29          - appendExamples: if this is nonzero then this node (and all children) 
30            will store the example 
31   
32        **Returns** 
33   
34          the classification of _example_ 
35   
36        **NOTE:** 
37          In the interest of speed, I don't use accessor functions 
38          here.  So if you subclass DecTreeNode for your own trees, you'll 
39          have to either include ClassifyExample or avoid changing the names 
40          of the instance variables this needs. 
41           
42      """ 
43      if appendExamples: 
44        self.examples.append(example) 
45      if self.terminalNode: 
46        return self.label 
47      else: 
48        val = example[self.label] 
49        if not hasattr(self,'nBounds'): self.nBounds = len(self.qBounds) 
50        if self.nBounds: 
51          for i,bound in enumerate(self.qBounds): 
52            if val < bound: 
53              val = i 
54              break 
55          else: 
56            val = i+1 
57        else: 
58          val = int(val) 
59        return self.children[val].ClassifyExample(example,appendExamples=appendExamples) 
60   
61 -  def SetQuantBounds(self,qBounds): 
62      self.qBounds = qBounds[:] 
63      self.nBounds = len(self.qBounds) 
64 -  def GetQuantBounds(self): 
65      return self.qBounds 
66     
67 -  def __cmp__(self,other): 
68      return cmp(type(self),type(other)) or \ 
69             cmp(self.qBounds,other.qBounds) or \ 
70             Tree.TreeNode.__cmp__(self,other) 
71   
72 -  def __str__(self): 
73      """ returns a string representation of the tree 
74   
75        **Note** 
76   
77          this works recursively 
78       
79      """ 
80      here = '%s%s %s\n'%('  '*self.level,self.name,str(self.qBounds)) 
81      for child in self.children: 
82        here = here + str(child) 
83      return here 
84