> x <- runif(10) > y <- runif(10) > cov(cbind(x,y)) x y x 0.1205034 0.02642830 y 0.0264283 0.09945432
I understand wanting to calculate covariance matrices. What I DON'T understand is wanting to do it using apply(). (And that's what looked like a homework problem, it's so artificial.) On Sat, 5 Oct 2024 at 01:41, Ivan Krylov via R-help <r-help@r-project.org> wrote: > > В Fri, 4 Oct 2024 20:28:01 +0800 > Steven Yen <st...@ntu.edu.tw> пишет: > > > Suppose I have two vectors, x and y. Is there a way > > to do the covariance matrix with “apply”. > > There is no covariance matrix for just two samples (vectors) 'x' and > 'y'. You can only get one covariance value for these. > > If you had a pair of vectors of _random variates_, the situation would > be different, but those are more abstract mathematical concepts. You > would need to sample every random variate, producing two matrices 'x' > and 'y' in order to calculate a covariance matrix for them. > > -- > Best regards, > Ivan > > ______________________________________________ > 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 https://www.R-project.org/posting-guide.html > 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 https://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.