Kia ora Grant The problem is that
feb[sample(nrow(feb),###),] randomly rearrangements the rows of all columns together, and hence doesn't altering the pairing. Try cor(feb[, col1], feb[sample(nrow(feb)), col2]) HTH .... Peter Alspach > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Grant Humphries > Sent: Thursday, 13 November 2008 8:57 a.m. > To: r-help@r-project.org > Subject: [R] sampling and testing > > Hello everyone, > > I have a dataset in the following format: > > col1 col2 > # # > # # > # # > # # > # # > # # > > > What I want to do is: > loop a random sample 10 times, and for each time it is > sampled I want to run a correlation between both columns. > What I have so far is this: > > >feb <- read.csv("corr.csv") # where the dataset is for February > >attach(feb) > >for(i in 1:10){ > > feb[sample(nrow(feb),###),] # "###" represents the > number of rows > > print(cor(col1,col2),) > >} > > > all this is doing for me is doing 10 correlations between all > 10 samples at the same time. What I was thinking was to do > something like: > - append a sample of the data: sample1 <- sample() > - do the correlation cor() > - remove that sample using rm(sample1) function > - repeat 9 more times > > > any help is greatly appreciated > > Cheers, > Grant Humphries > > > University of Alaska Fairbanks > -EWHALE-lab Irving I Rm 419 > 902 Koyukuk Dr. > Fairbanks, Alaska > 99775 > 907-474-7959 > [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. > The contents of this e-mail are privileged and/or confidential to the named recipient and are not to be used by any other person and/or organisation. If you have received this e-mail in error, please notify the sender and delete all material pertaining to this e-mail. ______________________________________________ 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.
