Answers.Body: <p>For a binary split, there are only three possible operations (or arguably only two if you consider one-hot encoding). Any other kind of split would simply not be binary. Almost every tree-based model is restricted to <em>binary</em> splits, due to the combinatorial explosion when considering ternary or even more complex splits.</p>
  
  <p>Of course you could write your own algorithm that uses recursive non-binary splits. Beware though that you'll be facing the same difficulty that has led the vast majority of algorithms to be limited to strictly binary splits.</p>
  
  <p>Have a look at <a href="https://stats.stackexchange.com/q/12187/176202">this related question</a>.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-04-15T00:58:28.497Z
Answers.LastActivityDate: 2019-04-15T00:58:28.497Z
Answers.UserDisplayName: Frans Rodenburg
Body: <p>In Decision Tree or Random Forest, each tree has a collection of decision nodes (in which each node has a threshold value) and a class labels (or regression values). </p>
  
  <p>I know that threshold values are used for comparison with a corresponding feature value. As far as I know, the comparison is performed either "&lt;", ">"  or "==" predicate.
  Anything else for the functions taking threshold value and a feature value as inputs??</p>
  
Tags: <decision-trees>
Title: What are possible functions assigned on decision nodes for decision tree prediction?
UserDisplayName: user9414424
ThreadText: # What are possible functions assigned on decision nodes for decision tree prediction?
  
  (Asked by: username_0 on 2019-04-13)
  
  In Decision Tree or Random Forest, each tree has a collection of decision nodes (in which each node has a threshold value) and a class labels (or regression values).
  
  I know that threshold values are used for comparison with a corresponding feature value. As far as I know, the comparison is performed either "<", ">" or "==" predicate.
  Anything else for the functions taking threshold value and a feature value as inputs??
  
  **Tags:** decision-trees
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2019-04-15. Score: 2 | Accepted answer
  
  For a binary split, there are only three possible operations (or arguably only two if you consider one-hot encoding). Any other kind of split would simply not be binary. Almost every tree-based model is restricted to *binary* splits, due to the combinatorial explosion when considering ternary or even more complex splits.
  
  Of course you could write your own algorithm that uses recursive non-binary splits. Beware though that you'll be facing the same difficulty that has led the vast majority of algorithms to be limited to strictly binary splits.
  
  Have a look at [this related question](https://stats.stackexchange.com/q/12187/176202).
  
  
  ---
  
  