# HHCART: An oblique decision tree

*D.C. Wickramarachchi*,
*B.L. Robertson*,
*M. Reale*,
*C.J. Price* and
*J. David Brown* ()

*Computational Statistics & Data Analysis*, 2016, vol. 96, issue C, 12-23

**Abstract:**
Decision trees are a popular technique in statistical data classification. They recursively partition the feature space into disjoint sub-regions until each sub-region becomes homogeneous with respect to a particular class. The basic Classification and Regression Tree (CART) algorithm partitions the feature space using axis parallel splits. When the true decision boundaries are not aligned with the feature axes, this approach can produce a complicated boundary structure. Oblique decision trees use oblique decision boundaries to potentially simplify the boundary structure. The major limitation of this approach is that the tree induction algorithm is computationally expensive. Hence, as an alternative, a new decision tree algorithm called HHCART is presented. The method uses a series of Householder matrices to reflect the training data at each non-terminal node during tree construction. Each reflection is based on the directions of the eigenvectors from each class’ covariance matrix. Considering of axis parallel splits in the reflected training data provides an efficient way of finding oblique splits in the unreflected training data. Experimental results show that the accuracy and size of HHCART trees are comparable with some benchmark methods. The appealing feature of HHCART is that it can handle both qualitative and quantitative features in the same oblique split.

**Keywords:** Oblique decision tree; Data classification; Statistical learning; Householder reflection; Machine learning (search for similar items in EconPapers)

**Date:** 2016

**References:** View references in EconPapers View complete reference list from CitEc

**Citations** Track citations by RSS feed

**Downloads:** (external link)

http://www.sciencedirect.com/science/article/pii/S0167947315002856

Full text for ScienceDirect subscribers only.

**Related works:**

This item may be available elsewhere in EconPapers: Search for items with the same title.

**Export reference:** BibTeX
RIS (EndNote, ProCite, RefMan)
HTML/Text

**Persistent link:** https://EconPapers.repec.org/RePEc:eee:csdana:v:96:y:2016:i:c:p:12-23

Access Statistics for this article

Computational Statistics & Data Analysis is currently edited by *S.P. Azen*

More articles in Computational Statistics & Data Analysis from Elsevier

Series data maintained by Dana Niculescu ().