Re: A question regarding a hyperbolic geometric function
- To: mathgroup at smc.vnet.net
- Subject: [mg86450] Re: [mg86396] A question regarding a hyperbolic geometric function
- From: Bob Hanlon <hanlonr at cox.net>
- Date: Tue, 11 Mar 2008 03:02:11 -0500 (EST)
- Reply-to: hanlonr at cox.net
v1 = Hypergeometric1F1[-26.9, -20.1, 30000] 5.86809071072512533577549124209830605005026`\ 15.954589770191005*^13007 Use exact values until evaluating the Hypergeometric1F1 with extended precision v2 = N[Hypergeometric1F1[-269/10, -201/10, 30000], 100] 5.86809071072500808515263985241332834422719\ \ 6477241041525402740155487068020893691436344\ \ 4849172908349727305685895816448516416585189\ 1451997662`100.*^13007 Although even without extra precision v1 is very close to v2 (v1 - v2)/v2 1.99810515261962031039159`2.2552081099371497\ *^-14 Bob Hanlon ---- "Ali K. Ozdagli" <ozdagli at gmail.com> wrote: > Hi, > > I am working with Mathematica in order to solve an ordinary > differential equation with several boundary conditions. It turned out > that the solution is Kummer confluent hypergeometric function, > HyperGeometric1F1[a,b,x]. My problem is that for the values of a, b > and x I am interested in, e.g. a=-26.9, b=-20.1, x=300000, the > numerical accuracy of Mathematica is very poor. > > Can somebody suggest me a way to improve the mathematical accuracy of > HyperGeometric1F1? I prefer a quick and easy way but also appreciate > any hard way. > > Best, > > Ali > > -- > > Ali K. Ozdagli > Ph.D. Student in Economics > at University of Chicago >