English: One-dimensional SOM versus PCA for data approximation. SOM is a red broken line with squares, 20 nodes. The first principal component is presented by a blue line Data points are the small grey circles. For PCA, the Fraction of variance unexplained in this example is 23.23%, for SOM it is 6.86%. Prepared with the Java applet, E.M. Mirkes, Principal Component Analysis and Self-Organizing Maps: applet. University of Leicester, 2011 http://www.math.le.ac.uk/people/ag153/homepage/PCA_SOM/PCA_SOM.html This applet is published under cc Attribution 3.0 unported license.