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Learn how to calculate PCA efficiently for high dimensional data, analyze EEG recordings using PCA, and apply Fast ICA for independent component analysis.
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Exercise 1Submission Monday 19 Dec, 2010 Delayed Submission: 4 points every week • How would you calculate efficiently the PCA of data where the dimensionality d is much larger than the number of vector observations n? Give the equation and explain • Download the EEG data that appears next to the exercise. It contains frames of EEG recordings from three electrodes. There are two class labels organized in two files • Extract PCAs from the data, test scatter plots of original data and after projecting onto the principal components, plot Eigen values. • Projections on which principal components are most correlated with the class labels?
Ex1. Part 2Submit to n.intrator@gmail.comsubject: Ex1 NC and last names Additional information about the data: • There are four groups in the data, you can seek separation between ESP and EHP, and between ESR and EHR. I suggest that you try both and see where separation is better.
Ex1. Part 2Submit to n.intrator@gmail.comsubject: Ex1 NC and last names • Given a high dimensional data, is there a way to know if all possible projections of the data are Gaussian? Explain - What if there is some additive Gaussian noise?
Ex1. (cont.) 2. Use Fast ICA (easily found on Google) http://www.cis.hut.fi/projects/ica/fastica/code/dlcode.html • Get the data from the Web site • Apply fastica to de-mix (different non-linear functions) • Devise ways to demonstrate that the new data is more independent than the original, how do you tell when non-linearity is best (show also graphically)
Ex1 – (Cont.) 3. Create a BCM learning rule which can go into the Fast ICA algorithm of Hyvarinen. • Run it on the previos data • Explain the results