# [R] Looking for simpler solution to probabilistic question

Rainer M Krug R.M.Krug at gmail.com
Tue Jan 15 14:33:21 CET 2008

```Berwin A Turlach wrote:
> G'day Rainer,
>
> On Tue, 15 Jan 2008 14:24:08 +0200
> Rainer M Krug <R.M.Krug at gmail.com> wrote:
>

>
>> ager <- range(age1) + range(age2)
>> ager <- ager[1]:ager[2]
>> pp1 <- c(cumsum(p1), rev(cumsum(rev(p1))))
>> pp2 <- c(cumsum(p2[-21]), rev(cumsum(rev(p2)))[-1])
>> pr <- pp1+pp2
>> pr <- pr/sum(pr)
>
>> all.equal(p, pr)
> [1] TRUE
>> all.equal(age, ager)
> [1] TRUE
>
>
> If this is more elegant is probably in the eye of the beholder, but it
> should definitely use less memory. :)

Thanks - interesting approach which is different to using the outer()

>
> BTW, I am intrigued, in which situation does this problem arise?  The
> time it takes the second process to finish seems to depend in a curious
> way on the time it took the first process to complete.....

These are two growth processes, where the first one is seedling growth
up to a certain X and the second one is adult growth from size X onwards
until it reaches a given final size.

I hope my calculations fit the process...

>
> Cheers,
>
> 	Berwin
>