The method is based on a repeated finite difference calculation with different step sizes and the use of the Richardson extrapolation (also known as the deferred approach to the limit) on the calculated eigenvalues.
Furthermore, based on the eigenvalues, one predominant factor similarly stands out, but some items are also loading on 3 other factors (Table 1).
Based on the estimated eigenvalues, the system predicts whether or not parametric roll occurred.
A fractional anisotropy (FA) map was computed based on the three eigenvalues of the tensor for quantifying the anisotropy of the deep white matter tracts.
The choice of factors was made based on the number of eigenvalues > 1, the number of eigenvalues that explained more than 60%% of the variance, an examination of the scree plot, and the interpretability of the results.
It is based on the conjecture that eigenvalues corresponding to 'noise' should decay geometrically, therefore, those eigenvalues should appear linear.
Some estimators are based on the eigenvalues of the correlation matrix, and others can be derived directly from the correlations without the need to calculate the eigenvalues [Chen and Liu, 2011; Cheverud, 2001; Moskvina and Schmidt, 2008].
Principal component analysis (PCA): Pores shapes and orientations were characterized based on the eigenvalues and eigenvectors of the covariance matrix, The axis length ratios of a/b and a/c were calculated to characterize pore shapes and their orientations relative to the imaging coordinates XYZ, XY reference axes are the bedding plane; Fig. 1).
We also give a similar result based on the eigenvalues of the information matrix.
Based on the eigenvalues and the scree plot, the initial EFA derived a two-factor solution.
This decision was based on the pattern of eigenvalues, the pattern of loadings and the interpretability of the solution.
