In Response To 'Re: Collecting terms in an expression'
Thanks a lot for replying to my post.
I think I made a mistake describing my question.
Summarizing the issue: I have a Multinormal Distribution Function of force components: Fx, Fy, Fz ..... Fx[n], Fy[n], Fz[n].
in the form of Exp[ a Fx^2 + a Fy^2 + a Fz^2 +......+ c Fx[n]^2 + c Fy[n]^2+c Fz[n]^2]
Now, I simply want Mathematica to simplify this function with this rule: Fx^2+Fy^2+Fz^2=F^2, ...., Fx[n]^2 +Fy[n]^2+Fz[n]^2=F[n]^2
So that at the end, it gives me Exp[ a F^2 + b F^2+..... c F[n]^2]....
I do really appreciate your help. I am new to Mathematica (this is my first work in Mathematica) and it is actually for my research.
Btw, Bill, one of your posts in physicsforum regarding multiple Integrals solved my other problem in this code! Thanks for that too!