You can always make variables in any system non dimensional. The whole field of chemical engineering works on this principle. Once you do that, you are free of

You can always make variables in any system non dimensional. The whole field of chemical engineering works on this principle. Once you do that, you are free of irregularities/issues that stem from scaling. Apply PCA after non dimensionalizing any system. Read More here : http://en.wikipedia.org/wiki/Nondimensionalization http://en.wikipedia.org/wiki/Nondimensionalization