[R] 2k-factorial design with 10 parameters
Hi, I'd like to apply a 2^k factorial design with k=10 parameters. Obviously this results in a quite long term for the model equation due to the high number of combinations of parameters. How can I specify the equation for the linear model (lm) without writing all combinations explicitly down by hand? Does a R command exist for this problematic? Thanks for your help in advance, Sven __ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Re: [R] 2k-factorial design with 10 parameters
Hi Sven, just use: lm(y~(x1+x2+x3+...+x10)^10) e.g., y - rnorm(5000) x1 - factor(sample(0:1, 5000, TRUE)) x2 - factor(sample(0:1, 5000, TRUE)) x3 - factor(sample(0:1, 5000, TRUE)) x4 - factor(sample(0:1, 5000, TRUE)) lm1 - lm(y~(x1+x2+x3+x4)^4) summary(lm1) I hope it helps. Best, Dimitris Dimitris Rizopoulos Ph.D. Student Biostatistical Centre School of Public Health Catholic University of Leuven Address: Kapucijnenvoer 35, Leuven, Belgium Tel: +32/16/336899 Fax: +32/16/337015 Web: http://www.med.kuleuven.ac.be/biostat http://www.student.kuleuven.ac.be/~m0390867/dimitris.htm - Original Message - From: Sven [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Tuesday, November 30, 2004 12:59 PM Subject: [R] 2k-factorial design with 10 parameters Hi, I'd like to apply a 2^k factorial design with k=10 parameters. Obviously this results in a quite long term for the model equation due to the high number of combinations of parameters. How can I specify the equation for the linear model (lm) without writing all combinations explicitly down by hand? Does a R command exist for this problematic? Thanks for your help in advance, Sven __ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html __ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Re: [R] 2k-factorial design with 10 parameters
On Tue, 30 Nov 2004, Sven wrote: I'd like to apply a 2^k factorial design with k=10 parameters. Obviously this results in a quite long term for the model equation due to the high number of combinations of parameters. How can I specify the equation for the linear model (lm) without writing all combinations explicitly down by hand? Does a R command exist for this problematic? I assume you mean k=10 factors (there are a lot more parameters). aov(y ~ .^10, data=mydata) will do what you are probably asking, if you have a data frame with response y and the ten factors. I'm not sure how you could analyse the 1000 odd lines of output, so reduce 10 to something sensible (like 2 or 3) -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UKFax: +44 1865 272595 __ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Re: [R] 2k-factorial design with 10 parameters
On 30 Nov 2004 at 12:59, Sven wrote: Hi, I'd like to apply a 2^k factorial design with k=10 parameters. Obviously this results in a quite long term for the model equation due to the high number of combinations of parameters. How can I specify the equation for the linear model (lm) without writing all combinations explicitly down by hand? Does a R command exist for this problematic? Hi Sven from ?lm The specification 'first*second' indicates the _cross_ of 'first' and 'second'. This is the same as 'first + second + first:second' and from ?formula ## Create a formula for a model with a large number of variables: xnam - paste(x, 1:25, sep=) (fmla - as.formula(paste(y ~ , paste(xnam, collapse= + If you change 1:25 to 1:10 and collapse to * and use fmla in your model you will get what you want (I suppose). But I woder if it has any sense. Cheers Petr Thanks for your help in advance, Sven __ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Petr Pikal [EMAIL PROTECTED] __ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Re: [R] 2k-factorial design with 10 parameters
On Tue, 30 Nov 2004, Sven wrote: I'd like to apply a 2^k factorial design with k=10 parameters. Obviously this results in a quite long term for the model equation due to the high number of combinations of parameters. How can I specify the equation for the linear model (lm) without writing all combinations explicitly down by hand? Does a R command exist for this problematic? Use expand.formula() in the AlgDesign package. -- Bob Wheeler --- http://www.bobwheeler.com/ ECHIP, Inc. --- Randomness comes in bunches. __ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
