On Oct 13, 2009, at 6:53 PM, Duncan Murdoch wrote:
On 13/10/2009 6:43 PM, David Winsemius wrote:
On Oct 13, 2009, at 5:12 PM, maram salem wrote:
Dear all,
I have the cdf of the following power fuction distribution:
F(y)=(y/350)^a ,0<y<350,
where " a " is some parameter with range a>0.
I want to use it as the argument of the discretize function of
the actuar package.
So I think I need to define this function to R so that if I
entered a=1, I get the following
F(y)=(y/350)
and if I entered a=4.5, I get the following
F(y) =(y/350)^4.5
........... and so on
I've tried
a<-vector(mode="numeric",length=1)
powercdf<-function(a,y)
(y/350)^a
But when I typed: powercdf(10,y)
instead of getting : (y/350)^10 (which is what I want)
I got : object y not found ??
I want y to remain as it is, a continous variable, not for
example seq(0,350).
Thank you in advance.
If you want symbolic algebra then use a system designed for such.
If you invoke a function in R you need to give it arguments for
evaluation ... to numerical values.
If you want a function that returns a function, that is also
possible.
> cdffn <- function(y, arg) return( function(y) {y^arg} )
But don't do it like that. If you do, you'll see things like this:
> power <- 10
> cdf10 <- cdffn(arg=power) # don't need y as an argument.
> power <- 1
> cdf10(1:10)
[1] 1 2 3 4 5 6 7 8 9 10
See my other post for a correct implementation using force().
Thank you, Duncan. I had seen your post (after hitting "send") but had
not realized how far out of itself a function might look for
arguments. You did mention the crucial aspect of force but I didn't
really get it until this further clue. Sometimes I'm a bit dense.
--
David
Duncan Murdoch
> cdf10 <- cdffn(y, 10)
> cdf10(1:10)
[1] 1 1024 59049 1048576
9765625 60466176 282475249 1073741824
[9] 3486784401 10000000000
David Winsemius, MD
Heritage Laboratories
West Hartford, CT
______________________________________________
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, MD
Heritage Laboratories
West Hartford, CT
______________________________________________
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.