On 11/12/2013 06:31 PM, andrea antonello wrote: > Hi Thomas, > >> that's exactly what we are looking for, so do not hesitate to ask questions. > > ok, I put together a small set of examples, which for now I put on a > wiki of the project I am doing this for (since I have access on that > one): http://code.google.com/p/jgrasstools/wiki/Eigenvectors > > Since in the 3d space I do not get the results I was hoping for, it > would be great if some expert could give me a hint. > > Let me know what you think.
Hi Andrea, are you sure that your eigenvectors are drawn correctly? I tried to reproduce your results with geogebra, and in my case the plane defined by the two eigenvectors with the least eigenvalue seems to split the values quite well, see this image: http://people.apache.org/~tn/pca.png The results from the computations: covariance: {0.7272727273,0.0,0.1818181818}, {0.0,0.3409090909,0.2272727273}, {0.1818181818,0.2272727273,0.2727272727}} lambda1 = 0.8056498828134406 v1 = {0.9015723558; 0.1900593782; 0.3886447222} lambda2 = 0.4874287594020183 v2 = {-0.3799516758; 0.7774478203; 0.5012101464} lambda3 = 0.04783044869363171 v3 = {-0.2068913033; -0.5995434259; 0.7731388421} The plane is constructed with v2 and v3. Thomas --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
