[R] Chi-square distribution probability density function:

[David Winsemius]

On Jul 21, 2010, at 1:18 PM, Knut Krueger wrote:

> David Winsemius schrieb:
>>
>>
>> And exactly why did you think I offered
>>
>> ?Chisquare
> I was completely on the wrong way, and tried to find a solution with  
> the formula instead to substitute the formula.
>
> So I tried to implement pchisq into the formula - and of course I  
> got wrong values ...

 > p <- function(x) ((0.5^(5/2))/gamma(5/2))*(x^((5/2)-1))*  
(2.718281828459^(-x/2))
 > integrate(p, 25.508, Inf)
0.0001111 with absolute error < 2.7e-05

Check result>>>>

 > pchisq(25.508,5)
[1] 0.9999
 > 1-pchisq(25.508,5)
[1] 0.0001111

>
> Thank's Knut

David Winsemius, MD
West Hartford, CT