[Ifeffit] Linear Combination Fitting - More Questions

[Gudrun Lisa Bovenkamp]

Hi everyone,

I just learned that before Athena there was no such program to check on 
all combinations, so it was not that confusing - or just more work?
I think this feature of Athena is very good tool, but when I really do 
not know what is in my sample how can it help?
I try to answer it myself and someone can correct me:
Certainly not all of my, say 10 reference spektra, are that similar that 
I can get several LCFs with the same say R-factor. So, I will get some 
clue to narrow the components. But still there can be, for example:
Standard-combi 1, 2, 3 equal to 1, 4, 6.
So,
  my analysis gives two solutions and one must be wrong, but both can be 
wrong. How can I tell?

Can a PCA help me in this case?

The results change significantly when I change the normalization. How do 
I know what is the 'correct' adjustment?  - Yes, I read the Athena 
turorials, but I got no answers from there.

I searched quite a while to find a complete documentation of the LCF 
formula used in Athena, but I could not find it.

Many thanks,
Lisa