Re: [R] Help with PCA data file prep and R code

2016-09-28 Thread Albin Blaschka
lege Station, TX 77840-4352 -Original Message- From: R-help [mailto:r-help-boun...@r-project.org] On Behalf Of Sarah Stinson Sent: Wednesday, September 21, 2016 10:25 AM To: r-help@r-project.org Subject: Re: [R] Help with PCA data file prep and R code Hello DRUGs, I'm new to R and w

Re: [R] Help with PCA data file prep and R code

2016-09-22 Thread David L Carlson
f Anthropology Texas A&M University College Station, TX 77840-4352 -Original Message- From: R-help [mailto:r-help-boun...@r-project.org] On Behalf Of Sarah Stinson Sent: Wednesday, September 21, 2016 10:25 AM To: r-help@r-project.org Subject: Re: [R] Help with PCA data file prep and R cod

Re: [R] Help with PCA data file prep and R code

2016-09-21 Thread Sarah Stinson
Hello DRUGs, I'm new to R and would appreciate some expert advice on prepping files for, and running, PCA... My data set consists of aquatic invertebrate and zooplankton count data and physicochemical measurements from an ecotoxicology study. Four chemical treatments were applied to mesocosm tanks

Re: [R] Help with PCA data file prep and R code

2016-09-21 Thread David L Carlson
It was not acceptable. Files with a .csv extension are stripped by the list. If you rename it as .txt it should survive. It appears that you have a controlled experimental design with explanatory and response variables, so why are you using pca which lumps them together? Alternatives might be ca

Re: [R] help with PCA

2013-03-16 Thread David L Carlson
half Of David Winsemius > Sent: Saturday, March 16, 2013 1:33 PM > To: john d > Cc: r-help@r-project.org > Subject: Re: [R] help with PCA > > > On Mar 16, 2013, at 8:49 AM, john d wrote: > > > Dear all, > > > > If I do a PCA like this: > > >

Re: [R] help with PCA

2013-03-16 Thread David Winsemius
On Mar 16, 2013, at 8:49 AM, john d wrote: > Dear all, > > If I do a PCA like this: > > dat<-matrix(rnorm(30),ncol=3) > res<-prcomp(dat) > > Now, imagine that I got new data that I want to project onto the > original PC axes. How do I do that? You can either read the help page or for worked e

Re: [R] Help with PCA

2011-12-30 Thread William Revelle
Sarah and elisacarli21 principal in the psych package will do principal components of a correlation or covariance matrix. ex: library(psych) principal(Thurstone,3,rotate="none") #First three principal components of the Thurstone correlation matrix #compare with eigen e <- eigen(Thurstone)

Re: [R] Help with PCA

2011-12-28 Thread Sarah Goslee
Hi, On Wed, Dec 28, 2011 at 7:54 AM, elisacarli21 wrote: > Dear all, > > I've  a correlation matrix with rows and columns headings. > I've two questions: > > 1) How can i import it in R, setting first row as row heading and first > column as column heading? read.table, with the appropriate optio