Re: RationalApproximation

*To*: mathgroup at smc.vnet.net*Subject*: [mg55065] Re: RationalApproximation*From*: "Carl K. Woll" <carlw at u.washington.edu>*Date*: Fri, 11 Mar 2005 04:20:40 -0500 (EST)*Organization*: University of Washington*References*: <d0p7q0$j44$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Scott, One typical idea is to write a wrapper function which stores the values of its arguments. Using one of the examples in the help for RationalInterpolation, RationalInterpolation[Exp[x],{x,2,4},{x,0,2}] we can modify as follows: pts={}; g[x_?NumericQ]:=(pts={pts,x};Exp[x]) RationalInterpolation[g[x],{x,2,4},{x,0,2}] Flatten[pts] The variable pts stores the set of values chosen as a nested list for efficiency reasons. The values you want are obtained by flattening pts. Carl Woll "Scott Guthery" <sguthery at mobile-mind.com> wrote in message news:d0p7q0$j44$1 at smc.vnet.net... > My bad. RationalInterpolation[]. The docs say: > > "There are two ways of using RationalInterpolation. If you just specify > a range in the independent variable, then the set of values is chosen > automatically in a way that ensures a reasonable approximation for the > degree of approximation you have chosen." > > The question is what is the set of values was chosen automatically. > > Cheers, Scott > > -----Original Message----- > From: DrBob [mailto:drbob at bigfoot.com] To: mathgroup at smc.vnet.net > Subject: [mg55065] Re: RationalApproximation > > I find no such function in Help for version 5.1.1, and no match for it > at WRI's documentation center. If searches like this always worked (but > they don't), that would mean there is no such function. You may have to > tell us what package the function comes from, before we can find any > clues on it. > > The Calculus`Pade` package has EconomizedRationalApproximation and > NumericalMath`Approximations` has a similar function called > RationalInterpolation, but I see no sign that either of them "ends up > using" any set of points at all. > > Bobby > > On Wed, 9 Mar 2005 06:34:28 -0500 (EST), Scott Guthery > <sguthery at mobile-mind.com> wrote: > >> Is there any way to get RationalApproximation n automatic mode to give > you back the set of points that it ended up using? >>Thanks for any insight. >>Cheers, Scott >> >> >> >> > > > > -- > DrBob at bigfoot.com > > >