Re: Precision issues
- To: mathgroup at smc.vnet.net
- Subject: [mg73531] Re: Precision issues
- From: "Ray Koopman" <koopman at sfu.ca>
- Date: Wed, 21 Feb 2007 01:47:16 -0500 (EST)
- References: <erelv2$7ol$1@smc.vnet.net>
On Feb 20, 3:27 am, mickey <m... at hotmail.com> wrote: > Hi, > > I am calculating certain integrals numerically and get back a number. > Now, is it possible to determine how many digits is that answer accurate > to? > > E.g., > > NIntegrate[ Exp[-p^2 - q^2], {p, 0, 10}, {q, 0, 10}, Method -> > MonteCarlo[24], MaxPoints -> 1000000] > > Gives, > > 0.791249 > > How many digits is this answer accurate to? > > Thanks, > -M The correct answer (to six digits) is 0.785398, so you have two acccurate digits. >From the Mathematica Help Browser, NIntegrate > Further Examples > MonteCarlo: "If the AccuracyGoal and PrecisionGoal are set to Automatic, they will be set to 2 in the methods MonteCarlo and QuasiMonteCarlo, and to 6 in all other methods."