[R] integrate

[David Winsemius]

On Nov 20, 2013, at 8:39 PM, David Winsemius wrote:

> 
> On Nov 20, 2013, at 7:12 PM, dan wang wrote:
> 
>> Hi all,
>> 
>> Can anyone help me with below integrate function?
>> 
>> Basically, I want to calculate the integral of  the sum of two kernel
>> density functions.
>> But the error shows that:
>> In x - a :
>> longer object length is not a multiple of shorter object length
>> 
>> y1 = rnorm(10)
>> y2 = rnorm(10)
>> fhat <- function(x,a){h=density(a)$bw;sum(dnorm((x-a)/h)/h/length(a))}
>> 
>> integrand1 <- function(p) {
>>            fhat(p,y1)+fhat(p,y2)
>>        }
>> integrate(integrand1,lower = -Inf, upper = Inf)
> 
> So, .... where is "a"?

Ignore that person. Try this:


Vintegrand <- Vectorize(integrand1)
integrate( Vintegrand, lower = -Inf, upper = Inf)
#----------------
2 with absolute error < 2.4e-05

David Winsemius
Alameda, CA, USA