aa file is： x 1 NA 2 y 1 NA 3 and r program is> aa<-read.table("aa",row.names=1) > bb<-cor(t(aa),method = "pearson",use="pairwise.complete.obs") > bbx y x 1 1 y 1 1 i am confused why the pearson correlation coefficients between x and y is 1 [[alternative HTML version deleted]]
On Fri, 24 Jun 2011, wang peter wrote:> aa file is? > x 1 NA 2 > y 1 NA 3 > > and r program is >> aa<-read.table("aa",row.names=1) >> bb<-cor(t(aa),method = "pearson",use="pairwise.complete.obs") >> bb > x y > x 1 1 > y 1 1 > > i am confused why the pearson correlation coefficients between x and y is 1You have two paired observations. Plot the points and draw the regression line. Every point is on the line (there are only two points). The correlation has to be 1. Mike
On Jun 24, 2011, at 1:58 PM, wang peter wrote:> aa file is? > x 1 NA 2 > y 1 NA 3 > > and r program is >> aa<-read.table("aa",row.names=1) >> bb<-cor(t(aa),method = "pearson",use="pairwise.complete.obs") >> bb > x y > x 1 1 > y 1 1 > > i am confused why the pearson correlation coefficients between x and > y is 1Because two points determine a line? -- David Winsemius, MD West Hartford, CT