Hi Hanna,

your function is essentially zero outside a short interval around 9. And the help page states: "If the function is approximately constant (in particular, zero) over nearly all its range it is possible that the result and error estimate may be seriously wrong."

You could try to integrate over a finite interval, say (7, 12).

Göran Broström

On 2018-02-06 19:40, li li wrote:
Sorry. I meant in the previous email that the function h() is a monotone
decreasing function. Thanks very much.

2018-02-06 13:32 GMT-05:00 li li <hannah....@gmail.com>:

Hi all,
   The function h below is a function of c and it should be a monotone
increasing function since the integrand is nonnegative and integral is
taken from c to infinity. However, as we can see from the plot, it is not
shown to be monotone. Something wrong with the usage of integrate function?
Thanks so much for your help.
     Hanna



h <- function(c){
     g <- function(x){pnorm(x-8.8, mean=0.4, sd=0.3,
lower.tail=TRUE)*dnorm(x, mean=9,sd=0.15)}
     integrate(g, lower=c, upper=Inf)$value}

xx <- seq(-20,20,by=0.001)
y <- xx
for (i in 1:length(xx)){y[i] <- h(xx[i])}
plot(xx, y)



        [[alternative HTML version deleted]]

______________________________________________
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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.


______________________________________________
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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.

Reply via email to