PRTools advanced examples
Readers new to PRTools should start by reading the PRTools User Guide.
There is a set of introductory examples that may serve as a part of an introductory PRTools course. These are based on code snippets that can be used by copy-paste-run next to a Matlab window,
Below the growing set of advanced PRTools example files is presented. These are published Matlab m-files that can be run by the user. In various documents references to these files are made.
A simple Kimia image classification, Introductory PR experiment on blob images. It loads the images, computes features, creates scatter plot and estimates the nearest neighbor classification error. | |
Classifiers, Introduction of defining, training and evaluating classifiers. | |
Learning curves, Learning curves for Bayes-Normal, Nearest Mean and Nearest Neighbor on the Iris dataset. Averages over 100 repetitions. | |
Cross-validation, A large experiment comparing the ability of several cross-validation procedures to determine the best of seven classifiers. | |
Feature curves, Feature curves for Bayes-Normal, on the Satellite dataset. | |
Feature selection 1, Examples of various feature selection procedures, organized per procedure. | |
Feature selection 2, Examples of various feature selection procedures, organized per classifier | |
The apparent error, Examples of the behavior of the apparent error for increasing training set size, dimensionality and complexity. | |
Bayes classifier uses a 2D examples of four normally distributed classes to show the Bayes classifier and how it can be approximated by qdc. A learning curve shows the speed of convergence to the Bayes error. | |
Adaboost introduction, Adaboost 2D examples based on perceptrons and decision stumps. | |
Adaboost comparison, Adaboost compared with other base classifier generators and combiners. | |
Combining classifiers, Introduction of stacked and parallel combining by fixed and trained combiners. | |
Multi-class classifiers, improved by using a trained combiner for post-processing | |
PCA versus classifier for feature reduction. An example comparing by feature curves the performance of PCA with that of a trained classifier for feature reduction in a multi-class problem. | |
Clustering, Introduction of various clustering techniques. | |
Semi-supervised learning by PCA, Illustrates that semi-supervised classification by PCA may be useful. |