Thanks to Brian Ripley for the time and effort put into developing the factanal package for R. I have found it very useful. However, in trying to replicate some results from previous research, I have run into the need for a couple of extensions and was wondering if they might find their way into future implementations. 1. Though maximum likelihood estimates might be more rigorous and appropriate as a default, it would be great to have the option of conducting factor analysis based on principle factors estimation. 2. When a Heywood case is encountered, error out saying such. Provide an option to perform the analysis anyway setting values to small positive numbers (although it might be statistically suspect, replicating results from other studies suggests to me that this is exactly what was done). Brett A. Magill, Associate Program Administration and Evaluation Health, Safety, and Community Services American Red Cross Phone: (703) 206-7731 Fax: (703) 206-7673 E-mail: bmagill at usa.redcross.org -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
On Tue, 1 May 2001, Magill, Brett wrote:> Thanks to Brian Ripley for the time and effort put into developing the > factanal package for R. I have found it very useful. However, in trying to > replicate some results from previous research, I have run into the need for > a couple of extensions and was wondering if they might find their way into > future implementations. > > 1. Though maximum likelihood estimates might be more rigorous and > appropriate as a default, it would be great to have the option of conducting > factor analysis based on principle factors estimation.principal? I don't write code for methods I believe should come with a severe health warning, but `patches may be accepted'.> 2. When a Heywood case is encountered, error out saying such. Provide an > option to perform the analysis anyway setting values to small positive > numbers (although it might be statistically suspect, replicating results > from other studies suggests to me that this is exactly what was done).Unfortunately the precise value of the `small positive value' can be critical. However, I don't get this: this is exactly what factanal does now, using 0.005 as the value. I don't trust the optimization enought to really declare a Heywood case adn give an error (and that is a comment on the likelihood surface, not the optimizer). -- Brian D. Ripley, ripley at stats.ox.ac.uk 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 272860 (secr) Oxford OX1 3TG, UK Fax: +44 1865 272595 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
gday R friends, can someone please direct me to the url for factanal? I cant see it in the contributed list on cran, nor on V&R's site. thanks, John Strumila On Tue, 1 May 2001, Magill, Brett wrote:> Thanks to Brian Ripley for the time and effort put into developing the > factanal package for R. I have found it very useful. However, in tryingto... -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
gday Brian, Obviously I didn't look hard enough; I should have done a cran search and I was using an old help file. thanks, John Strumila -----Original Message----- From: Prof Brian D Ripley [mailto:ripley at stats.ox.ac.uk] Sent: Wednesday, 2 May 2001 4:12 PM To: Strumila, John Cc: 'r-help at lists.R-project.org' Subject: RE: [R] Factor Analysis On Wed, 2 May 2001, Strumila, John wrote:> gday R friends, > > can someone please direct me to the url for factanal? I cant see it inthe> contributed list on cran, nor on V&R's site.It's part of the R distribution, package mva, since R 1.2.1: CHANGES IN R VERSION 1.2.1 NEW FEATURES o New functions factanal(), varimax(), promax() and examples in package mva. -- Brian D. Ripley, ripley at stats.ox.ac.uk 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 272860 (secr) Oxford OX1 3TG, UK Fax: +44 1865 272595 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._