On 10/4/2024 5:13 PM, Steven Yen wrote: > Pardon me!!! > > What makes you think this is a homework question? You are not > obligated to respond if the question is not intelligent enough for you. > > I did the following: two ways to calculate a covariance matrix but > wonder how I might replicate the results with "apply". I am not too > comfortable with the online documentation of "apply". > > > set.seed(122345671) > n<-3 > x<-rnorm(n); x [1] 0.92098449 0.80940115 > 0.60374785 > cov1<-outer(x-mean(x),x-mean(x))/(n-1); cov1 [,1] [,2] > [,3] [1,] 0.0102159207 0.00224105983 -0.0124569805 [2,] 0.0022410598 > 0.00049161983 -0.0027326797 [3,] -0.0124569805 -0.00273267965 > 0.0151896601 > cov2<-(x-mean(x))%*%t((x-mean(x)))/(n-1); cov2 [,1] > [,2] [,3] [1,] 0.0102159207 0.00224105983 -0.0124569805 [2,] > 0.0022410598 0.00049161983 -0.0027326797 [3,] -0.0124569805 > -0.00273267965 0.0151896601 > > On 10/4/2024 4:57 PM, Uwe Ligges wrote: >> Homework questions are not answered on this list. >> >> Best, >> Uwe Ligges >> >> >> >> On 04.10.2024 10:32, Steven Yen wrote: >>> The following line calculates standard deviations of a column vector: >>> >>> se<-apply(dd,1,sd) >>> >>> How can I calculate the covariance matrix using apply? Thanks. >>> >>> ______________________________________________ >>> 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. [[alternative HTML version deleted]]
______________________________________________ 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.
