Re: numeric integration

*To*: mathgroup at smc.vnet.net*Subject*: [mg81181] Re: numeric integration*From*: "C. Seja" <p5secr2 at uni-jena.de>*Date*: Fri, 14 Sep 2007 03:48:57 -0400 (EDT)*References*: <fcb40h$fm3$1@smc.vnet.net>

found two simple solutions: 1) writing f[y_?NumericQ] := NIntegrate[Sin[x + y], {x, 0, 1}] instead of f = NIntegrate[Sin[x + #], {x, 0, 1}] & 2) writing NIntegrateF[f, {0, 0.1}] instead of NIntegrate[f[x], {x, 0, 0.1}] with the definition NIntegrateF[f_ , a_] := Module[{F}, F[x_?NumericQ] = f[x]; NIntegrate[F[x], {x, a[[1]], a[[2]]}] ]; c. seja > Hi, > > I'd like to intergate a function f with NIntegrate: > NIntegrate[f[x], {x, 0, 0.1}] > > But this doesn't work if, i.e. > > f = NIntegrate[Sin[x + #], {x, 0, 1}] & > > It will give a wrong result (0.7 instead of 0.05). Why? I mean, I can > evaluate f at any point without problems, i.e. f[0.1] gives 0.37. So why > doesn't > > NIntegrate[f[x], {x, 0, 0.1}] > > work? It doesn't even give a warning! So, is there a proper way to do this > (without using one two-dimensional NIntegrate)? > > Regards > > C. Seja > > >

**Follow-Ups**:**Re: Re: numeric integration***From:*Vivek Joshi <vivekj@wolfram.com>