Finding the percentage of points in a designated vector
On Nov 9, 2012, at 9:52 AM, Ricky Corp wrote:
I am new to R and learned to program 10 years ago in C++. I am currently
working a project that looks at the distribution of randomly generated beta
values. I take 20 random beta values find their sum, repeat 100000 times.
Here is my code that it took me 4 hours to get
s=numeric(length=100000)
for(i in 1:100000){
pop=(rbeta(n=20,shape1=2,shape2=1))
s[i]=sum(pop)
}
So now I have them all in in vector, I would like to maybe sort or count
them to see how many are less than or equal to 10,
sum( s <= 10 ) # Adding up TRUE/FALSE as 1/0
but am guessing there is a density r function that may be easier then that.
Your subject line suggested something else however. There is a quantile function. Perhaps: quantile(s, c(0.025, 0.975) ) # 2.5th and 97.5th percentile points
David Winsemius, MD Alameda, CA, USA