Hi Armin, Please copy the list on your emails. Providing your matrix A (or some other reproducible example) would be useful to anyone who wanted to help you. It is easy to do by copying the output from your console from running:
dput(A) This would at least let us try out your code on your data. On Wed, Jul 20, 2011 at 3:28 AM, a.me...@yahoo.co.uk <a.me...@yahoo.co.uk> wrote: > Thanks for your continued support Joshua! > > I first have run prcomp() and now use principal() to reduce the principal > components with varimax. > > Here is the code so far..... > > print("START.............................") > print("reading in Matrix A") > A=read.delim('C:/Work/Docs/Merlyn Stuff/Leachate/A.txt') > print("printing the initial Matrix A") > A > print("scaling determinands in Matrix A to maximum") > ncols=ncol(A) > c=1 > while (c <= ncols) > { > V=A[,c] > max=max(V) > V=V/max > A[,c]=V > c=c+1 > } > > print("printing Matrix A with scaled determinands") > A > print("performing PCA of Matrix A to Matrix Apc") > Apc = prcomp(A) > print("calculating scores of Apc as Matrix Apcs") > > Apcs = as.matrix(A) %*% as.matrix(Apc$rotation) > > print("printing scores from the PCA (Matrix Apcs)") > Apcs > > print("performing Varimax rotation of Matrix Apcs to Matrix Apcsv") > > library(psych) > Apcsv<-principal(Apcs,nfactors = 3,rotate = "varimax") > > print("scaling Matrix Apcsv to range (0,1)") > Apcsv=Apcsv-min(Apcsv) > Apcsv=Apcsv*(1/max(Apcsv)) > print("printing Matrix Apcsv scaled to range (0,1)") > Apcsv > > But there is an error on this part..... > >> Apcsv<-principal(Apcs,nfactors = 3,rotate = "varimax") > Error in eigen(r) : infinite or missing values in 'x' > In addition: Warning message: > In sqrt(diag(r)) : NaNs produced > > Have you got any ideas? I have already tried to tell you that what you are doing does not make sense to me. The only other advice I can offer is to seek the advice or help of a local statistician. > > Regards, > > Armin > > > I have got so far as to use the principal function > > On 20/07/2011 03:56, Joshua Wiley wrote: > > On Mon, Jul 18, 2011 at 10:48 AM, a.me...@yahoo.co.uk > <a.me...@yahoo.co.uk> wrote: > > Ok thank you Josh. > > Basically I have a matrix A with 7 rows and 18 columns. > > If i < j (where i is the number of rows in your matrix and j is the > number of columns), then the determinant of the covariance (or > correlation) matrix |Sigma_A| will be 0 (or very near zero, you can > easily convince yourself of this by running det(cov(matrix(rnorm(90), > 9))) as many times as you need). From Cramer's Rule, if the > determinant of the matrix is 0, there is not a unique solution > (clarifications/corrections are welcome if any of this is wrong). > > > What I am told is I need the 'varimax rotated scores from the PCA analysis > of matrix A' > > Who told you that? Is this homework? You could look at the > ?principal function in package "psych". That said, if this is > homework I would talk with your instructor more, and if this is > anything beyond an exercise (i.e., has real world implications), I > would seek the advice/help of a local statistician. > > I can choose from 3 up to 7 components. My problem is how to carry out the > above. > > Have you any ideas? > > Would appreciate your help! > > Armin > > On 18/07/2011 18:07, Joshua Wiley wrote: > > Hi, > > You need to explain what you want to do. This is not a software > issue, you simply cannot create more uncorrelated variables than you > have observations. > > Josh > > On Mon, Jul 18, 2011 at 8:53 AM, a.me...@yahoo.co.uk > <a.me...@yahoo.co.uk> wrote: > > Hi, > > May I ask a question about a thread > https://stat.ethz.ch/pipermail/r-help/2005-March/068365.html? > > I understand I need to use prcomp instead of princomp when i have less > units than variables. > > However, when I use prcomp the scores is NULL. How can I overcome this? > > Regards, > > Armin > > -- > Kind Regards, > > Armin Mewes > Groundesign > 10 Jerusalem street > Belfast > BT7 1QN > > Tel. (0044)(0)2890280887 > Email. enquir...@groundesign.net > www. www.groundesign.net > > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > > > > -- > Kind Regards, > > Armin Mewes > Groundesign > 10 Jerusalem street > Belfast > BT7 1QN > > Tel. (0044)(0)2890280887 > Email. enquir...@groundesign.net > www. www.groundesign.net > > > -- > Kind Regards, > > Armin Mewes > Groundesign > 10 Jerusalem street > Belfast > BT7 1QN > > Tel. (0044)(0)2890280887 > Email. enquir...@groundesign.net > www. www.groundesign.net -- Joshua Wiley Ph.D. Student, Health Psychology University of California, Los Angeles https://joshuawiley.com/ ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.