Be the first to rate this file! 21 Downloads (last 30 days) File Size: 4.19 KB File ID: #34527
image thumbnail

3D visualization of GMM learning via the EM algorithm


Johannes (view profile)


10 Jan 2012 (Updated )

The evolution of a GMM in the EM algorithm is visualized by interpolating between iterations.

| Watch this File

File Information

This is a 3D visualization of how the Expectation Maximization algorithm learns a Gaussian Mixture Model for 3-dimensional data.

--How it works--
The data is either read in or generated in general-covariance gaussian clusters. For desired values of k (number of Gaussians to fit), a movie is played showing the evolution of the GMM through the iterations of the EM algorithm. The true model is only available at each iteration (viewed as an anchor frame in a movie), so the illusion of movement of the 3D Gaussians (displayed as ellipsoids at 1 standard deviation) is given by interpolating enough "frames" in between these anchor frames.

Required Products MATLAB
MATLAB release MATLAB 7.14 (R2012a)
Tags for This File   Please login to tag files.
Please login to add a comment or rating.
10 Jan 2012

color gradient added to data points to show the certainty that it belongs to the nearest Gaussian

10 Jan 2012

updated description

13 Jan 2012

reduced overhead

15 Jan 2012

changed mean initialization from 'at data mean with small noise' to 'at data points chosen at random' (usually gives better clustering)

28 Mar 2012

Corrected bug in EM implementation

04 Mar 2013

Cleaned up code, improved plotting, coloring, added full-covariance capabilities

04 Mar 2013

Simplified 2D plotting option, stream-lined code

Contact us