MathGroup Archive 1997

[Date Index] [Thread Index] [Author Index]

Search the Archive

problems with precision

  • To: mathgroup at smc.vnet.net
  • Subject: [mg7646] problems with precision
  • From: Axel Breuer <u970870 at student.dtu.dk>
  • Date: Tue, 24 Jun 1997 03:36:09 -0400 (EDT)
  • Sender: owner-wri-mathgroup at wolfram.com

Hello,

I am a french student doing a trainee on mathematica. There is another
team having the same project as I have but it's working with Maple.
We had to calculate with high accuracy (more than 20 digits) the solution
of a 2 dimensional non-linear system. The problem to solve was very easy.
But Maple and Mathematica agreed only on the 15 first digits. I used the
function SetPrecision. Is there another function to set calculus precision
?

Here is the listing of my routine in Mathematica :

rr=Table[FindRoot[{x+Cos[y]*Sinh[x]==0,y+Sin[y]*Cosh[x]==0},{x,N[Abs[Cos[(2*p-1)*Pi+Pi/4]]Sqrt[((2*p-1)*Pi+Pi/4/Sin[(2*p-1)*Pi+Pi/4]^2)-1]]},{y,(2*p-1)*Pi+Pi/4}]
, {p, 1, 20, 1}]

rr=SetPrecision[rr,20]

ListPlot[{x, y} /. rr]

r={x, y} /. rr;




  • Prev by Date: algorithm for a sum
  • Next by Date: Re: mathematica problem
  • Previous by thread: algorithm for a sum
  • Next by thread: Re: problems with precision