Re: Integrate vs. NIntegrate

*To*: mathgroup at smc.vnet.net*Subject*: [mg51423] Re: Integrate vs. NIntegrate*From*: "David W. Cantrell" <DWCantrell at sigmaxi.org>*Date*: Sun, 17 Oct 2004 03:05:07 -0400 (EDT)*References*: <ckqnbf$nh0$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

carlos at colorado.edu (Carlos Felippa) wrote: > Which one is the correct answer? > > f=2+Cos[2 x]+ I*Sin[2 x]; > > Print[ N[Simplify[ Integrate[Log[f],{x,-Pi,Pi}]/(2*Pi)]] //InputForm]; > 0.34657359027997264 + 1.5707963267948966*I > > Print[ NIntegrate[Log[f],{x,-Pi,Pi}]/(2*Pi) //InputForm]; > 0.6931471805599428 + 0.*I > > I believe the second one, have doubts about the first. The second one is correct (except for the last few decimal places). What version are you using? In version 5.0.0.0, f = 2 + Cos[2*x] + I*Sin[2*x]; Simplify[Integrate[Log[f], {x, -Pi, Pi}]/(2*Pi)] Log[2] N[%] 0.6931471805599453 David Cantrell