Re: [R] reflecting a PCA biplot

2011-08-10 Thread Gavin Simpson
On Tue, 2011-08-09 at 22:57 +1000, Andrew Halford wrote: Hi Listers, I am trying to reflect a PCA biplot in the x-axis (i.e. PC1) but am not having much success. In theory I believe all I need to do is multiply the site and species scores for the PC1 by -1, which would effectively flip the

[R] reflecting a PCA biplot

2011-08-09 Thread Andrew Halford
Hi Listers, I am trying to reflect a PCA biplot in the x-axis (i.e. PC1) but am not having much success. In theory I believe all I need to do is multiply the site and species scores for the PC1 by -1, which would effectively flip the biplot. I am creating a blank plot using the plot command and

Re: [R] reflecting a PCA biplot

2011-08-09 Thread Allan Engelhardt (CYBAEA)
Something like opar- par(mfcol = c(1, 2)) z- prcomp(USArrests, scale = TRUE) biplot(z, cex = 0.5) z$x[,1]- -z$x[,1] z$rotation[,1]- -z$rotation[,1] biplot(z, cex = 0.5, xlab = -PC1) par(opar) perhaps? Allan On 09/08/11 13:57, Andrew Halford wrote: Hi Listers, I am trying to reflect a PCA