Re: [R] Programing and writing function help
Thank- you all for you suggestions and help. I have now resolved my issue. This help forum is one of the things that makes R a great platform for statistics. Stephen Cole Marine Ecology Lab Saint Francis Xavier University On Wed, Oct 8, 2008 at 8:07 AM, Erin Hodgess [EMAIL PROTECTED]wrote: Actually, you will have duplicates with 400 pairs. Here you will have 13^2 pairs with replacement and 13*12 pairs without replacement and with regard to order. How about this: z - unique(x) y - expand.grid(z[1:13],z[1:13]) xx - y[,1] != y[,2] y[xx,] Just another thought. Erin On Wed, Oct 8, 2008 at 5:55 AM, Erin Hodgess [EMAIL PROTECTED] wrote: For all possible pairs, you'll have 20^2 pairs. This is a way to do it: expand.grid(x[1:20],x[1:20]) HTH, Erin On Wed, Oct 8, 2008 at 4:43 AM, Jim Lemon [EMAIL PROTECTED] wrote: Stephen Cole wrote: ... I have a vector of 20 values x - c(20,18, 45, 16, 47, 47, 15, 26, 14,14,12,16,35,27,18,94,16,26,26,30) 1. I want to select random pairs from this data set but do it without replacement exhaustively matrix(x[sample(1:20,20)],nrow=2) then step through the columns of the resulting matrix I know i can select random pairs without replacement using sample(N,n,replace=F) However i am wondering if there is any way to get 10 random pairs from this data set without repeating any of the data points that is to say if i got a (20, 94) for one pair, i would like to get 9 other pairs from the data without again getting 20 or 94? 2. The second thing i would like to do is be able to select all possible pairs of numbers and calculate each pairs variance. I think you want to use the combn function, but you are going to get a lot of pairs... Jim __ 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. -- Erin Hodgess Associate Professor Department of Computer and Mathematical Sciences University of Houston - Downtown mailto: [EMAIL PROTECTED] -- Erin Hodgess Associate Professor Department of Computer and Mathematical Sciences University of Houston - Downtown mailto: [EMAIL PROTECTED] [[alternative HTML version deleted]] __ 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] Programing and writing function help
Stephen Cole wrote: ... I have a vector of 20 values x - c(20,18, 45, 16, 47, 47, 15, 26, 14,14,12,16,35,27,18,94,16,26,26,30) 1. I want to select random pairs from this data set but do it without replacement exhaustively matrix(x[sample(1:20,20)],nrow=2) then step through the columns of the resulting matrix I know i can select random pairs without replacement using sample(N,n,replace=F) However i am wondering if there is any way to get 10 random pairs from this data set without repeating any of the data points that is to say if i got a (20, 94) for one pair, i would like to get 9 other pairs from the data without again getting 20 or 94? 2. The second thing i would like to do is be able to select all possible pairs of numbers and calculate each pairs variance. I think you want to use the combn function, but you are going to get a lot of pairs... Jim __ 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] Programing and writing function help
Actually, you will have duplicates with 400 pairs. Here you will have 13^2 pairs with replacement and 13*12 pairs without replacement and with regard to order. How about this: z - unique(x) y - expand.grid(z[1:13],z[1:13]) xx - y[,1] != y[,2] y[xx,] Just another thought. Erin On Wed, Oct 8, 2008 at 5:55 AM, Erin Hodgess [EMAIL PROTECTED] wrote: For all possible pairs, you'll have 20^2 pairs. This is a way to do it: expand.grid(x[1:20],x[1:20]) HTH, Erin On Wed, Oct 8, 2008 at 4:43 AM, Jim Lemon [EMAIL PROTECTED] wrote: Stephen Cole wrote: ... I have a vector of 20 values x - c(20,18, 45, 16, 47, 47, 15, 26, 14,14,12,16,35,27,18,94,16,26,26,30) 1. I want to select random pairs from this data set but do it without replacement exhaustively matrix(x[sample(1:20,20)],nrow=2) then step through the columns of the resulting matrix I know i can select random pairs without replacement using sample(N,n,replace=F) However i am wondering if there is any way to get 10 random pairs from this data set without repeating any of the data points that is to say if i got a (20, 94) for one pair, i would like to get 9 other pairs from the data without again getting 20 or 94? 2. The second thing i would like to do is be able to select all possible pairs of numbers and calculate each pairs variance. I think you want to use the combn function, but you are going to get a lot of pairs... Jim __ 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. -- Erin Hodgess Associate Professor Department of Computer and Mathematical Sciences University of Houston - Downtown mailto: [EMAIL PROTECTED] -- Erin Hodgess Associate Professor Department of Computer and Mathematical Sciences University of Houston - Downtown mailto: [EMAIL PROTECTED] __ 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] Programing and writing function help
For all possible pairs, you'll have 20^2 pairs. This is a way to do it: expand.grid(x[1:20],x[1:20]) HTH, Erin On Wed, Oct 8, 2008 at 4:43 AM, Jim Lemon [EMAIL PROTECTED] wrote: Stephen Cole wrote: ... I have a vector of 20 values x - c(20,18, 45, 16, 47, 47, 15, 26, 14,14,12,16,35,27,18,94,16,26,26,30) 1. I want to select random pairs from this data set but do it without replacement exhaustively matrix(x[sample(1:20,20)],nrow=2) then step through the columns of the resulting matrix I know i can select random pairs without replacement using sample(N,n,replace=F) However i am wondering if there is any way to get 10 random pairs from this data set without repeating any of the data points that is to say if i got a (20, 94) for one pair, i would like to get 9 other pairs from the data without again getting 20 or 94? 2. The second thing i would like to do is be able to select all possible pairs of numbers and calculate each pairs variance. I think you want to use the combn function, but you are going to get a lot of pairs... Jim __ 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. -- Erin Hodgess Associate Professor Department of Computer and Mathematical Sciences University of Houston - Downtown mailto: [EMAIL PROTECTED] __ 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] Programing and writing function help
Hello R users My goal is to use R to write functions for and automate a series of analyses i would like to do on a large data set. The calculations are not very difficult in themselves, however they will be very time consuming (Plus I think R will be extremely useful and this is another excuse to learn how to program). I have a vector of 20 values x - c(20,18, 45, 16, 47, 47, 15, 26, 14,14,12,16,35,27,18,94,16,26,26,30) 1. I want to select random pairs from this data set but do it without replacement exhaustively I know i can select random pairs without replacement using sample(N,n,replace=F) However i am wondering if there is any way to get 10 random pairs from this data set without repeating any of the data points that is to say if i got a (20, 94) for one pair, i would like to get 9 other pairs from the data without again getting 20 or 94? 2. The second thing i would like to do is be able to select all possible pairs of numbers and calculate each pairs variance. I think i will need a for loop here but I am unsure of how to do the programing. I am reading two books on S and s-plus now and hope they are some help. I thought i would also post on this list and get some expert advice for the more experienced R users Thank-you very much Stephen Cole Marine Ecology Lab Saint Francis Xavier University [[alternative HTML version deleted]] __ 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] Programing and writing function help
Here is one way that might work for you: x - c(20,18, 45, 16, 47, 47, 15, 26, 14,14,12,16,35,27,18,94,16,26,26,30) # create a matrix of pairs matrix(sample(x), ncol=2) [,1] [,2] [1,] 14 16 [2,] 27 20 [3,] 26 16 [4,] 47 15 [5,] 35 47 [6,] 16 18 [7,] 14 12 [8,] 18 26 [9,] 45 26 [10,] 94 30 # all possible pairs # create a matrix of the dimensions x*x and the the indices of the lower triangle ind - which(lower.tri(matrix(1,length(x), length(x))), arr.ind=TRUE) # create the pairs x.pairs - cbind(x[ind[,1]], x[ind[,2]]) str(x.pairs) num [1:190, 1:2] 18 45 16 47 47 15 26 14 14 12 ... head(x.pairs) [,1] [,2] [1,] 18 20 [2,] 45 20 [3,] 16 20 [4,] 47 20 [5,] 47 20 [6,] 15 20 On Tue, Oct 7, 2008 at 1:50 PM, Stephen Cole [EMAIL PROTECTED] wrote: Hello R users My goal is to use R to write functions for and automate a series of analyses i would like to do on a large data set. The calculations are not very difficult in themselves, however they will be very time consuming (Plus I think R will be extremely useful and this is another excuse to learn how to program). I have a vector of 20 values x - c(20,18, 45, 16, 47, 47, 15, 26, 14,14,12,16,35,27,18,94,16,26,26,30) 1. I want to select random pairs from this data set but do it without replacement exhaustively I know i can select random pairs without replacement using sample(N,n,replace=F) However i am wondering if there is any way to get 10 random pairs from this data set without repeating any of the data points that is to say if i got a (20, 94) for one pair, i would like to get 9 other pairs from the data without again getting 20 or 94? 2. The second thing i would like to do is be able to select all possible pairs of numbers and calculate each pairs variance. I think i will need a for loop here but I am unsure of how to do the programing. I am reading two books on S and s-plus now and hope they are some help. I thought i would also post on this list and get some expert advice for the more experienced R users Thank-you very much Stephen Cole Marine Ecology Lab Saint Francis Xavier University [[alternative HTML version deleted]] __ 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. -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem that you are trying to solve? __ 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.
