[R] Integrate inside function

[R. Michael Weylandt]

I believe the difficulty is that the integrate function isn't
vectorized: add this line and you should be good

pmixedgamma3 <- Vectorize(pmixedgamma3)

Read ? Vectorize for details if you only need to vectorize certain arguments.

Michael

On Thu, Mar 15, 2012 at 6:08 AM, Mauro Rossi <mauro.rossi at irpi.cnr.it> wrote:
> Dear R users,
>    first I take this opportunity to greet all the R community for your
> continuous efforts.
> I wrote a function to calculate the pdf and cdf of a custom distribution
> (mixed gamma model).
> The function is the following:
>
> pmixedgamma3 <- function(y, shape1, rate1, shape2, rate2, prev)
>        {
>        density.function<-function(x)
>                {
>                shape1=shape1
>                rate1=rate1
>                shape2=shape2
>                rate2=rate2
>                prev=prev
>
>  fun<-prev*((rate1^shape1)/gamma(shape1)*(x^(shape1-1))*exp(-rate1*x)) +
> (1-prev)*((rate2^shape2)/gamma(shape2)*(x^(shape2-1))*exp(-rate2*x))
>                return(fun)
>                }
>        den<-density.function(y)
>        p.mixedgamma<-integrate(f=density.function,lower=0,upper=y)
>        return(list(density=den,cumdensity=p.mixedgamma$value))
>        }
>
> Why doesn't this calculate cumdensity (p.mixedgamma) in case x is a vector?
>
> For instance try:
> pmixedgamma3(c(10,20),shape1=10,rate1=1,shape2=10,rate2=1,prev=0.5)
>
> As you can see cumdensity is calculated just for the first x value.
>
> Thanks in advance
> Best
> Mauro
>
> --
> Mauro Rossi
> Istituto di Ricerca per la Protezione Idrogeologica
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> Italia
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>
>
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