Re: [R] How do you test for consecutivity?
Charles C. Berry: Are the numbers 1:30 equiprobable?? If so, you can find the probability by direct enumeration. Or by a simple formula: * Probabilities of Consecutive Integers in Lotto * Author(s): Stanley P. Gudder and James N. Hagler * Source: Mathematics Magazine, Vol. 74, No. 3 (Jun., 2001), pp. 216-222 * Publisher: Mathematical Association of America * Stable URL: http://www.jstor.org/stable/2690723 -- Karl Ove Hufthammer __ 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.
[R] How do you test for consecutivity?
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. -- View this message in context: http://www.nabble.com/How-do-you-test-for-%22consecutivity%22--tp16959748p16959748.html Sent from the R help mailing list archive at Nabble.com. __ 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.
Re: [R] How do you test for consecutivity?
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. Vec - c(2, 28, 31, 4, 27) Vec [1] 2 28 31 4 27 # Sort the vector sort(Vec) [1] 2 4 27 28 31 # Get differences between sequential elements diff(sort(Vec)) [1] 2 23 1 3 # Are any differences == 1? any(diff(sort(Vec)) == 1) [1] TRUE See ?sort, ?diff and ?any for more information On your last question, if the data are all numeric and each experiment contains 30 elements from which you select five, then you can store the data in a N x 30 matrix, where N is the number of source data sets. The result could be stored in a N x 5 matrix. You can then run your test of sequential members as follows, presuming 'Res' contains the N x 5 result matrix: prop.table(table(apply(Res, 1, function(x) any(diff(sort(x)) == 1))) The output will be the proportion TRUE/FALSE of rows that have sequential elements. HTH, Marc Schwartz __ 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.
Re: [R] How do you test for consecutivity?
How about this
result - numeric(10)
for(i in 1:10){
x - sample(1:30, 5, replace = FALSE)
x - sort(x)
result[i] - any(diff(x) == 1)
}
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Anthony28
Sent: Tuesday, April 29, 2008 8:52 AM
To: r-help@r-project.org
Subject: [R] How do you test for consecutivity?
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.
--
View this message in context:
http://www.nabble.com/How-do-you-test-for-%22consecutivity%22-
-tp16959748p16959748.html
Sent from the R help mailing list archive at Nabble.com.
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Re: [R] How do you test for consecutivity?
This will work: my.list - c(2, 28, 31, 4, 27) sort(my.list) diff(sort(my.list)) any(diff(sort(my.list)) == 1) the middle two lines are only to illustrate what's going on. Best wishes! Charles Annis, P.E. [EMAIL PROTECTED] phone: 561-352-9699 eFax: 614-455-3265 http://www.StatisticalEngineering.com -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Anthony28 Sent: Tuesday, April 29, 2008 8:52 AM To: r-help@r-project.org Subject: [R] How do you test for consecutivity? 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. -- View this message in context: http://www.nabble.com/How-do-you-test-for-%22consecutivity%22--tp16959748p16 959748.html Sent from the R help mailing list archive at Nabble.com. __ 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. __ 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.
Re: [R] How do you test for consecutivity?
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)}
#Note that I am counting both numbers in a consecutive pair. For
example, the vector c(1,2,6,9,10) will contain 4 consecutive numbers. I
think this is what you wanted do do, right?
#Next, generate a matrix with 1000 columns (one for each experiment) and
5 rows (the five numbers in each experiment). Note the use of the
'replicate' function to generate multiple sets of random numbers
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@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.
Re: [R] How do you test for consecutivity?
On Tue, 29 Apr 2008, 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. Are the numbers 1:30 equiprobable?? If so, you can find the probability by direct enumeration. mat - combn(30,5) # each column happens to be in order tab - table( mat[2:5,]-mat[1:4,]==1, col(mat[1:4,]) ) table(tab[2,]) 0 1 2 3 4 65780 59800 15600 130026 prop.table( table(tab[2,] != 0 ) ) FALSE TRUE 0.4615946 0.5384054 If the numbers are not equiprobable, you will need to weight the values of tab[2,] according to the probability of each column of mat. HTH, Chuck -- View this message in context: http://www.nabble.com/How-do-you-test-for-%22consecutivity%22--tp16959748p16959748.html Sent from the R help mailing list archive at Nabble.com. __ 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. Charles C. Berry(858) 534-2098 Dept of Family/Preventive Medicine E mailto:[EMAIL PROTECTED] UC San Diego http://famprevmed.ucsd.edu/faculty/cberry/ La Jolla, San Diego 92093-0901 __ 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.
Re: [R] How do you test for consecutivity?
Hey Anthony,
My previous function may not work in all cases. Say one of the
experiments yields these numbers:
1,2,3,6,7
Would you say that the proportion of consecutive numbers is 100%? If
so, this will work:
prop.diff=function(x){
d=diff(sort(x))
prop=sum((c(0,d==1)+c(d==1,0))0)
prop=prop/length(x)
return(prop)}
This function first identifies which numbers in your original vector are
part of a sequence of consecutive numbers.
Julian
Julian Burgos wrote:
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)}
#Note that I am counting both numbers in a consecutive pair. For
example, the vector c(1,2,6,9,10) will contain 4 consecutive numbers. I
think this is what you wanted do do, right?
#Next, generate a matrix with 1000 columns (one for each experiment) and
5 rows (the five numbers in each experiment). Note the use of the
'replicate' function to generate multiple sets of random numbers
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@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.
__
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.
Re: [R] How do you test for consecutivity?
I'd just like to thank all you guys for stepping in so promptly with help. I haven't yet had a chance to implement any of your code yet, but just by looking over what you've suggested, I think I have enough to guide me. So thanks once again! -- View this message in context: http://www.nabble.com/How-do-you-test-for-%22consecutivity%22--tp16959748p16973477.html Sent from the R help mailing list archive at Nabble.com. __ 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.
