Hi r-help-boun...@r-project.org napsal dne 01.02.2010 18:14:04:
> > Dear Petr, > > The intention is to get a ratio value for every observations (1400 obs) for > every variable (4 variables). Well, maybe that mat<-matrix(runif(12),4,3) ratiomat<-t(t(mat)/vec) > > And from the ratios, I would like to rank the variables based on how many > times the variable being the highest among 4 of them (or the total number of > being the highest ratios, out of 1400 times). Eh. I am stupid enough not to understand what you mean. Which variables? Do you mean maximum in each column? apply(ratiomat,2, max) [1] 0.9686974 0.4097230 0.3085468 > > >From the 1400 by 4 dataset, I ran a principal component analysis and I'll use > only the first PC for the calculation of the ratios. > > The PC (a vector) will has 4 values for each variables. > > The ratios actually representing the contribution of a variable divide by the > total contribution from the first PC. I can not say much about principal components analysis above what is described in help page. > > Does it make sense to you now? Thank you very much for giving a response. I > really appreciate it. Not much. Reproducible code could be more informative then describing a problem by your words. Regards Petr > > Best regards, > ayu > > > > > ________________________________ > From: Petr Pikal [via R] <ml-node+1458931-701777...@n4.nabble.com> > > Sent: Mon, 1 February, 2010 15:58:50 > Subject: Odp: How to repeat "for" function? > > Hi > few comments > > [hidden email] napsal dne 01.02.2010 14:51:17: > > > > > Dear Users, > > > > I have one problem here, I tried many time and even read a few notes on > > writing function but still..... > > > > > > Can anyone help me on how to simplify Part B (please refer the > programming > > below), so that I don't have to repeat the calculation of "num" and "r" > ? > > > > > > > > > Thank you very much..every help is very much appreciated... > > > > > > ## Part A > > n=1400 > > m=matrix(c(0,0,0,0),4,1) > > m2=matrix(c(0,2,0,0),4,1) > > c4<-matrix(c(1.0,0.2,-0.5,0.3,0.2,1,0.2,-0.5,-0.5,0.2,1,0.2,0.3,-0.5,0.2,1), > 4,4,byrow=T) > > set.seed(428) > > X=mvrnorm(n,m2,c4) > > X.pca<-princomp(X) > > loadings(X.pca) > > pc=X.pca$loadings[,1] > > > > ##  Part B > > num1=rep(1:n) > > is same as > num1 <- 1:n > > > for(i in 1:n)num1[i]=pc[1]%*%X[i,1] > > If I understand what the above code does I am a bit surprised > > pc[1] is > > pc[1] > [1] 0.525037 > > for each number in cycle > > X[i,1] is again a number > > > X[1,1] > [1] 0.7512862 > > X[2,1] > [1] 0.5020333 > > > > so it basically  results in > > pc[1] * X[,1] > > which you can compute for all 4 columns by > > kronecker(pc, X, "*") > > But I wonder if this is what you really want. > > Maybe you shall think it over again and try with some smaller manageable > subset lit > > smallX <- X[1:5,] > > do all your computation and if it does not produce what you want, specify > what you want. > > Regards > Petr > > > > > num2=rep(1:n) > > for(i in 1:n)num2[i]=pc[2]%*%X[i,2] > > num3=rep(1:n) > > for(i in 1:n)num3[i]=pc[3]%*%X[i,3] > > num4=rep(1:n) > > for(i in 1:n)num4[i]=pc[4]%*%X[i,4] > > > > den=rep(1:n) > > for(i in 1:n)den[i]=pc%*%X[i,] > > > > > > r1=num1/den > > r2=num2/den > > r3=num3/den > > r4=num4/den > > MLAV=sum(r2>r1 & r2>r3 & r2>r4) > > MLAV > > > > Best regards, > > ayu > > > > > > -- > > View this message in context: http://n4.nabble.com/How-to-repeat-for-function- > > tp1458806p1458806.html > > Sent from the R help mailing list archive at Nabble.com. > > > > ______________________________________________ > > [hidden email] 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. > > ______________________________________________ > [hidden email] 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. > > > ________________________________ > > View message @ http://n4.nabble.com/How-to-repeat-for-function-tp1458806p1458931.html > To unsubscribe from How to repeat "for" function?, click here. > > > > > -- > View this message in context: http://n4.nabble.com/How-to-repeat-for-function- > tp1458806p1459009.html > Sent from the R help mailing list archive at Nabble.com. > > [[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. ______________________________________________ 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.
