For the time being I am assuming the relationship across variables is linear. I want get the values first and detailed examining of the relationship will follow later.
On Mon, Aug 22, 2022 at 12:23 PM Ebert,Timothy Aaron <teb...@ufl.edu> wrote: > > I (maybe) agree, but I would go further than that. There are assumptions > associated with the test that are missing. It is not clear that the > relationships are all linear. Regardless of a "significant outcome" all of > the relationships need to be explored in more detail than what is provided in > the correlation test. > > Multiplicity adjustment as in : > https://www.sciencedirect.com/science/article/pii/S0197245600001069 is not an > issue that I can see in these data from the information provided. At least > not in the same sense as used in the link. > > My first guess at the meaning of "multiplicity adjustment" was closer to the > experimentwise error rate in a multiple comparison procedure. > https://dictionary.apa.org/experiment-wise-error-rateEssentially, the type 1 > error rate is inflated the more test you do and if you perform enough tests > you find significant outcomes by chance alone. There is great significance in > the Redskins rule: https://en.wikipedia.org/wiki/Redskins_Rule. > > A simple solution is to apply a Bonferroni correction where alpha is divided > by the number of comparisons. If there are 250, then 0.05/250 = 0.0002. > Another approach is to try to discuss the outcomes in a way that makes sense. > What is the connection between a football team's last home game an the > election result that would enable me to take another team and apply their > last home game result to the outcome of a different election? > > Another complication is if variables x2 through x250 are themselves > correlated. Not enough information was provided in the problem to know if > this is an issue, but 250 orthogonal variables in a real dataset would be a > bit unusual considering the experimentwise error rate previously mentioned. > > Large datasets can be very messy. > > > Tim > > -----Original Message----- > From: Bert Gunter <bgunter.4...@gmail.com> > Sent: Monday, August 22, 2022 12:07 PM > To: Ebert,Timothy Aaron <teb...@ufl.edu> > Cc: Val <valkr...@gmail.com>; r-help@R-project.org (r-help@r-project.org) > <r-help@r-project.org> > Subject: Re: [R] Correlate > > [External Email] > > ... But of course the p-values are essentially meaningless without some sort > of multiplicity adjustment. > (search on "multiplicity adjustment" for details). :-( > > -- Bert > > > On Mon, Aug 22, 2022 at 8:59 AM Ebert,Timothy Aaron <teb...@ufl.edu> wrote: > > > > A somewhat clunky solution: > > for(i in colnames(dat)){ > > print(cor.test(dat[,i], dat$x1, method = "pearson", use = > > "complete.obs")$estimate) > > print(cor.test(dat[,i], dat$x1, method = "pearson", use = > > "complete.obs")$p.value) } > > > > Rather than printing you could set up an array or list to save the results. > > > > > > Tim > > > > -----Original Message----- > > From: R-help <r-help-boun...@r-project.org> On Behalf Of Val > > Sent: Monday, August 22, 2022 11:09 AM > > To: r-help@R-project.org (r-help@r-project.org) <r-help@r-project.org> > > Subject: [R] Correlate > > > > [External Email] > > > > Hi all, > > > > I have a data set with ~250 variables(columns). I want to calculate > > the correlation of one variable with the rest of the other variables > > and also want the p-values for each correlation. Please see the > > sample data and my attempt. I have got the correlation but unable to > > get the p-values > > > > dat <- read.table(text="x1 x2 x3 x4 > > 1.68 -0.96 -1.25 0.61 > > -0.06 0.41 0.06 -0.96 > > . 0.08 1.14 1.42 > > 0.80 -0.67 0.53 -0.68 > > 0.23 -0.97 -1.18 -0.78 > > -1.03 1.11 -0.61 . > > 2.15 . 0.02 0.66 > > 0.35 -0.37 -0.26 0.39 > > -0.66 0.89 . -1.49 > > 0.11 1.52 0.73 -1.03",header=TRUE) > > > > #change all to numeric > > dat[] <- lapply(dat, function(x) as.numeric(as.character(x))) > > > > data_cor <- cor(dat[ , colnames(dat) != "x1"], dat$x1, method = > > "pearson", use = "complete.obs") > > > > Result > > [,1] > > x2 -0.5845835 > > x3 -0.4664220 > > x4 0.7202837 > > > > How do I get the p-values ? > > > > Thank you, > > > > ______________________________________________ > > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > > https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fstat > > .ethz.ch%2Fmailman%2Flistinfo%2Fr-help&data=05%7C01%7Ctebert%40ufl > > .edu%7C871d5009dd3c455f398f08da84585e4a%7C0d4da0f84a314d76ace60a62331e > > 1b84%7C0%7C0%7C637967812337328788%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4w > > LjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C > > &sdata=3iAfMs1QzQARKF3lqUI8s43PX4IIkgEuQ9PUDyUtpqY%3D&reserved > > =0 PLEASE do read the posting guide > > https://nam10.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.r > > -project.org%2Fposting-guide.html&data=05%7C01%7Ctebert%40ufl.edu% > > 7C871d5009dd3c455f398f08da84585e4a%7C0d4da0f84a314d76ace60a62331e1b84% > > 7C0%7C0%7C637967812337328788%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwM > > DAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C& > > sdata=v3IEonnPgg1xTKUzLK4rJc3cfMFxw5p%2FW6puha5CFz0%3D&reserved=0 > > and provide commented, minimal, self-contained, reproducible code. > > > > ______________________________________________ > > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > > https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fstat > > .ethz.ch%2Fmailman%2Flistinfo%2Fr-help&data=05%7C01%7Ctebert%40ufl > > .edu%7C871d5009dd3c455f398f08da84585e4a%7C0d4da0f84a314d76ace60a62331e > > 1b84%7C0%7C0%7C637967812337328788%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4w > > LjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C > > &sdata=3iAfMs1QzQARKF3lqUI8s43PX4IIkgEuQ9PUDyUtpqY%3D&reserved > > =0 PLEASE do read the posting guide > > https://nam10.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.r > > -project.org%2Fposting-guide.html&data=05%7C01%7Ctebert%40ufl.edu% > > 7C871d5009dd3c455f398f08da84585e4a%7C0d4da0f84a314d76ace60a62331e1b84% > > 7C0%7C0%7C637967812337328788%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwM > > DAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C& > > sdata=v3IEonnPgg1xTKUzLK4rJc3cfMFxw5p%2FW6puha5CFz0%3D&reserved=0 > > and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
