digital-idiot / RotationForest

Implementation of the Rotation Forest by Rodriques et al. 2006

Rotation Forest

Simple derived implementation of Rotation Forest algorithm^{[1, 2]} based upon sklearn's random forest module.

Algorithm

for tree in trees:
	split the attributes in the training set into K non-overlapping subsets of equal size.
	bootstrap þ% of the data from each K dataset and use the bootstrap data in the following steps:
		- Run PCA on the i-th subset in K. Retain all principal components. For every feature j in the Kth subsets, we have a principal component a.
		- Create a rotation matrix of size n X n where n is the total number of features. Arrange the principal component in the matrix such that the components match the position of the feature in the original training dataset.
		- Project the training dataset on the rotation matrix.
		- Build a decision tree with the projected dataset
		- Store the tree and the rotation matrix.

• Rotation forest has been implemented both as classifier^[1] and regressor^[2].

^{[1] J. J. Rodriguez, L. I. Kuncheva, and C. J. Alonso, “Rotation Forest: A New Classifier Ensemble Method,” IEEE Trans. Pattern Anal. Mach. Intell., vol. 28, no. 10, pp. 1619–1630, Oct. 2006, doi: 10.1109/tpami.2006.211. [2] C. Pardo, J. F. Diez-Pastor, C. García-Osorio, and J. J. Rodríguez, “Rotation Forests for regression,” Applied Mathematics and Computation, vol. 219, no. 19, pp. 9914–9924, Jun. 2013, doi: 10.1016/j.amc.2013.03.139.}

---

Toy Benchmark

• Random Forest Classifier

• Random Forest Regressor