Stokes V eigenvalue spectrum of a V410-Tau observation (solid line) and the mean eigenvalue spectrum obtained from a bootstrap randomization process (dashed line) for the first 100 dimensions of rotation phase 0.014. The magnitude of the eigenvalues of the corresponding observation covariance matrix and the mean eigenvalues of all randomized matrices are plotted over the corresponding subspace dimension index. The crossing point at dimension 27 marks the dimension from which on the individual eigenprofiles contain no more significant information.