Hi David,

Thank you so much.

-Cassie


On Sun, Jun 16, 2013 at 9:19 PM, David Winsemius <dwinsemius@comcast.net>wrote:

>
> On Jun 16, 2013, at 7:15 PM, David Winsemius wrote:
>
> >
> > On Jun 16, 2013, at 6:46 PM, cassie jones wrote:
> >
> >> Dear R-users,
> >>
> >> I am trying to integrate a function using integrate command in R.
> >> The function is as follows,
> >>
> >> integrand
> >> function(x,a)
> >> {
> >> exp(-0.5*a*(1+x^2))/(1+x^2)
> >> }
> >>
> >> Now while I want to integrate it using the command integrate, I get the
> >> following error,
> >>
> >> integrate(integrand(x,2),0,inf)
> >>
> >> Error in match.fun(f) :
> >> 'integrand(x, 2)' is not a function, character or symbol
> >>
> >> I understand that the argument of integrate needs to be solely
> dependent on
> >> x, that is why it is not able to recognize the input as there are both x
> >> and a. But I need to have the integrand dependent on the variable a.
> Does
> >> anyone know how can I handle the problem? Any help is appreciated.
> >
> > You also misspelled `Inf`
> >
> >> integrand <- function(x,a=2)
> > + {
> > + exp(-0.5*a*(1+x^2))/(1+x^2)
> > + }
> >>
> >> integrate(integrand,0,Inf)
> > 0.247085 with absolute error < 3e-05
>
> Can also use '..." argument:
>
> ?integrate
>
>  integrand <- function(x,a)
>  {
>  exp(-0.5*a*(1+x^2))/(1+x^2)
>  }
>
>  integrate(integrand,0,Inf, a=2)
> # 0.247085 with absolute error < 3e-05
> >
> >
> >>
> >> Thanks in advance.
> >>
> >> -Cassie
> >>
> >>      [[alternative HTML version deleted]]
> >>
> >> ______________________________________________
> >> R-help@r-project.org mailing list
> >> https://stat.ethz.ch/mailman/listinfo/r-help
> >> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> >> and provide commented, minimal, self-contained, reproducible code.
> >
> > David Winsemius
> > Alameda, CA, USA
> >
> > ______________________________________________
> > R-help@r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.
>
> David Winsemius
> Alameda, CA, USA
>
>

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