From: Julian Burgos <jmburgos_at_u.washington.edu>

Date: Tue, 29 Apr 2008 10:07:19 -0700

R-help_at_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. Received on Tue 29 Apr 2008 - 18:12:59 GMT

Date: Tue, 29 Apr 2008 10:07:19 -0700

Hey Anthony,

There must be many ways to do this. This is one of them:

#First, define a function to calculate the proportion of consecutive numbers in a vector.

prop.diff=function(x){

d=diff(sort(x))

prop=(sum(d==1)+1)/length(x)

return(prop)}

selection=replicate(1000,sort(sample(1:30,5)))

#Third, use the apply function to apply the function we defined above to each column of the matrix

diffs=apply(selection,2,prop.diff)

# This will give you a vector with the 1000 proportions of consecutive numbers

Julian

Anthony28 wrote:

> I need to use R to model a large number of experiments (say, 1000). Each

*> experiment involves the random selection of 5 numbers (without replacement)
**> from a pool of numbers ranging between 1 and 30.
**>
**> What I need to know is what *proportion* of those experiments contains two
**> or more numbers that are consecutive. So, for instance, an experiment that
**> yielded the numbers 2, 28, 31, 4, 27 would be considered a "consecutive =
**> true" experiment since 28 and 27 are two consecutive numbers, even though
**> they are not side-by-side.
**>
**> I am quite new to R, so really am puzzled as to how to go about this. I've
**> tried sorting each experiment, and then subtracting adjacent pairs of
**> numbers to see if the difference is plus or minus 1. I'm also unsure about
**> whether to use an array to store all the data first.
**>
**> Any assistance would be much appreciated.
*

R-help_at_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. Received on Tue 29 Apr 2008 - 18:12:59 GMT

Archive maintained by Robert King, hosted by
the discipline of
statistics at the
University of Newcastle,
Australia.

Archive generated by hypermail 2.2.0, at Tue 29 Apr 2008 - 20:30:44 GMT.

*
Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help.
Please read the posting
guide before posting to the list.
*