Fisher discriminant analysis (Mardia et al, 1979) is similar to principal component analysis in that it uses a multidimensional normal distribution to model the 24 clusters.

Linear discriminant analysis is typically carried out using Fisher's method. This method relies on the sample averages and covariance matrices computed from the different groups constituting the ...

V. Yu. Urbakh, Linear Discriminant Analysis: Loss of Discriminating Power When a Variate is Omitted, Biometrics, Vol. 27, No. 3 (Sep., 1971), pp. 531-534 ...