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Re: Derivative Evaluation


To evaluate the xk derivative of f[x1, x2, x3,...,xn] at
{a1, a2, a3,...,an}, user

     Derivative[0, 0, 0,...,1,...,0][f][a1, a2, a3,...,an]

where the "1" appears in position k between the first set of 

[]'s and all other entries are 0.  


For higher (pure) derivatives, replace the 1 with the order of 

the derivative you want.  Mixed derivatives result when more than
one non-zero entry appears inside the first set of []'s.

--Lou Talman

Begin forwarded message:

John Cigana wrote:
>
> Hello,
>
> I have a 7 parameters multivariate function. i.e. y = f(x1..x7).
>
> I am able to correctly find the partial derivative for each parameter.
>
> However, I can't seem to be able to evaluate my derivative at a given
> point. i.e. f'(x1=0.01, x2=0.5, x3=0.02, ... x7=0.05) = Value !
>
> Any insight on the subject ?? Any help appreciated !
>
> Thanks,
>
> JOHN CIGANA,



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