Plot Eigen Vectors

 >> covX=[3.1163    1.2956;      1.2956    0.5810];
 >> [Evec Eval]=eig(covX);

for this how to plot Eigen vectors ?

Answer 1

[Andrei Bobrov]

plot(Evec)

Answer 2

[Bjorn Gustavsson]

Look on the file exchange for arrow plotting functions, there are at least 2 very good submissions. Those will be the "natural" choice for plotting eigenvectors for 2 and 3-D cases. For higher dimensions plot will do it, unless you have some direct geometrical interpretations of your covariance matrix - then you might prefer imagesc(reshape(Evec,[s1,s2])).

HTH

[Raviteja]

Can you please give the exact link of the file in file exchange.

and more over what is s1, s2 in your code?

[Bjorn Gustavsson]

1, http://lmgtfy.com/?q=arrow+matlab+file+exchange the first, third, second and fourth link gets you to the better ones.

2, For example if you have a covariance matrix built from data taken at a number (n>>3) of atmospheric altitude levels of say the pressure, then the eigenvectors are best plotted with plot(evec). Each eigenvector correspons (handwavingly talking) to a 1-D basis function. If your covariance matrix are built from data taken at nZ altitudes at nL latitudes then it is better to look at the eigenvectors one by one: imagesc(reshape(Evec(i1,:),[nZ,nL] - s1 & s2 above)) - that way you'd see the shape of the 2-D variation of the eigenvectors. Here the size of the covariance matrix would be (nZ*nL)x(nZ*nL).