Re: [R] t() prior to data rotation

2011-08-20 Thread christopher stratton
Well, did you try it with a simple test case to see what comes out? > Do you have a sample "mydata.txt" file so you know how it's ordered in the > first place? > > Carl > > > From: christopher stratton > Date: Fri, 19 Aug 2011 23:10:07 -0400 > > >

[R] t() prior to data rotation

2011-08-19 Thread christopher stratton
Dear All, I have come upon an R-mode PCA protocol that uses the following arguments, where "mydata.txt" is an nxm matrix of n objects and m variables: > a <- read.table("mydata.txt") > b <- t(a) > c <- prcomp(b) > c$rotation The user then plots the coordinates given by c$rotation (PC1 and PC2) a

[R] PCA Using prcomp()

2011-08-14 Thread christopher stratton
Hey guys, I am new to R and apologize for the basic question - I do not mean to offend. I have been using R to perform PCA on a set several hundred objects using a set of 30 descriptors. From the results generated by prcomp(), is there a way to print a matrix showing the contributions of the orig