Nm. Faber et al., GENERALIZED RANK ANNIHILATION METHOD .2. BIAS AND VARIANCE IN THE ESTIMATED EIGENVALUES, Journal of chemometrics, 8(3), 1994, pp. 181-203
Rank annihilation factor analysis (RAFA) is a method for multicomponen
t calibration using two data matrices simultaneously, one for the unkn
own and one for the calibration sample. In its most general form, the
generalized rank annihilation method (GRAM), an eigenvalue problem has
to be solved. In this second paper expressions are derived for predic
ting the bias and variance in the eigenvalues of GRAM. These expressio
ns are built on the analogies between a reformulation of the eigenvalu
e problem and the prediction equations of univariate and multivariate
calibration. The error analysis will also be performed for Lorber's fo
rmulation of RAFA. It will be demonstrated that, depending on the size
of the eigenvalue, large differences in performance must be expected.
A bias correction technique is proposed that effectively eliminates t
he bias if the error in the bias estimate is not too large. The derive
d expressions are evaluated by Monte Carlo simulations. It is shown th
at the predictions are satisfactory up to the limit of detection. The
results are not sensitive to an incorrect choice of the dimension of t
he factor space.