Re: Derivative Evaluation

*To*: mathgroup at smc.vnet.net*Subject*: [mg6056] [mg6051] Re: [mg6017] Derivative Evaluation*From*: Lou Talman <me at talmanl.mscd.edu>*Date*: Sun, 16 Feb 1997 01:11:58 -0500*Sender*: owner-wri-mathgroup at wolfram.com

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,