Percent Effect of variables in equation

[Gaenn]

Anyidea on how to obtain the percentage or weight of each variable in an equation?

for example:

BBC = (X+1)*(a*b*c)/(U*V)

what would each variable X,a,b,c,U,V weight in percentage in equation BBC?

Appreciate it.

[Bob S]

Take the partial derivatives of each variable to get its effect on the value of BBC. If any of the variables are correlated, then it is a little more complicated; you will need correlation coefficients.
If all of the variables have gaussian uncertainty distributions, then all the terms should be summed in quadrature to get the total variance on BBC.

[0xDEADBEEF]

Maybe one should note that the weight depends on the values at which the function is evaluated.