similar to: R for Psychometrics

Version 1.5 of the MiscPsycho package had been uploaded to CRAN (should hit mirrors in a day or so). This package has a set of functions that may be useful for psychometric applications. The package has been updated to include the following: 1) All functions (where appropriate) now use standard formula arguments 2) All functions now use S3 print and summary methods 3) Help files have been

I sent a query to R-Help about the availability of nonmetric multidimensional scaling (MDS) algorithms in R. I would like to thank Tony Rossini, Jonathan Baron, Sundar Dorai-Raj, and Brian Ripley for helpful replies. The gist of the replies is that isoMDS in the MASS library provides Kruskal's method for nonmetric MDS, sammon in the MASS library provides Sammon's nonlinear mapping method

A student of mine wants to use R to do some nonmetric multidimensional scaling. According to the R FAQ, there's a package called pcurve that computes multidimensional scaling solutions, but I was not able to locate it the contrib page (I am a Windows user with R version 1.4.1). Can anyone tell me whether it is possible to do nonmetric multidimensional scaling with R, and if so, how? John

http://www.cuddyvalley.org/psychoR/code now contains version 1.4 of ca.R There are already many versions of CA and CCA in various R packages, but this one has some unique features, so maybe it is useful. The function ca() can do simple CA, but it also allows for linear restrictions on the row and column scores (they can be restricted to be in the span of a number of covariates). Thus the

Dear R-helpers, I am running metaMDS in the vegan package, which uses isoMDS in MASS, to perform Nonmetric Multidimentional Scaling (NMDS). I have seen some authors report a p-value for the NMDS ordination based on randomization of the dataset. As I understand it this is meant to compare the stress in your dataset to multiple runs of randomized data. I do not see a way to perform such a test in

Hello I will be applying MDS (actually Isomap) to make a psychological "concept map" of the similarities between N concepts. I would like to scale to a large number of concepts, however, the resulting N*(N-1) pairwise similarities is prohibitive for a user survey. I'm thinking of giving people random subsets of the pairwise similarities. Does anyone have recommendations for this

Many new things at http://www.cuddyvalley.org/psychoR/ The scalassoc package, which fits exponential distance association models to indicator matrices, it now at version 1.0.0. It seems to be robust and can analyze large examples easily. It is a major improvement (in speed and robustness) over the distassoc package, which is at the same site. scalassoc does something neat (if you like

I have a dissimilarity dataset with the form: 1 1 dissimilarity value 1 2 ... 1 3 1 4 2 2 2 3 2 4 ... I would like to do nonmetric multidimensional scaling with this data, but I am having trouble using this format. I would like to either find a function that accepts this format or find a way to easily convert this format to a matrix for use with existing functions. Thanks!

Hi, I am stuck in one problem when doing nonmetric multidimensional scaling. I use the function 'metaMDS' in the package 'vegan' to work on the presence/absence community data. The problem is when two samples are identical (dissimilarity = 0), metaMDS cannot work with zero dissimilarity. I don't want to delete the duplicates as they are true samples from different locations.

One of the outcomes of useR! 2006 is that JSS is planning to publish a series of special volumes. They will be guest edited (I have guest editors already, although somewhat tentative in some cases). Each volume will have 5-10 issues (articles) of the usual JSS format. Psychometrics in R Political Methodology in R Econometrics in R Social Science Methodology in R Spectroscopy/Chemometrics in R

Dear UserR's, The smacof package (see also our PsychoR repository on http://r-forge.r-project.org/projects/psychor/) is uploaded on CRAN. This package provides the following approaches of multidimensional scaling (MDS) based on stress minimization by means of majorization (smacof): - Simple smacof on symmetric dissimilarity matrices - smacof for rectangular matrices (unfolding models) -

The Journal of Statistical Software was founded by Jan de Leeuw in 1996. Currently, there are 26 volumes with 260 aricles and the journal publishes about 4 new volumes per year. The web address is www.jstatsoft.org. All articles are pdf files, since 2005 all produced from JSS LaTeX templates. JSS is edited by Jan de Leeuw, since 2005 jointly with Achim Zeileis of the Wirtschaftsuniversität Wien.

At www.jstatsoft.org we now have three special volumes Volume 22, Ecology and Ecological Modelling in R (Thomas Kneib and Thomas Petzoldt, eds.) Volume 20, Psychometrics in R (Jan de Leeuw and Patrick Mair, eds.) Volume 18, Spectroscopy and Chemometrics in R (Kate Mullen and Ivo van Stokkum, eds.) Coming soon -- Econometrics in R -- Political Methodology in R Gleam in my eye --

in 2007 we will publish seven volumes of JSS (four of them special volumes). Volume 18 Spectroscopy and Chemometrics in R Volume 19 regular Volume 20 Psychometrics in R Volume 21 regular Volume 22 Ecology and Ecological Modeling in R Volume 23 is being started, it is a regular volume, and may not fill up completely. Volume 24 is 'Statistical Modeling of Social Networks with

Hi, I am trying to create 3 mds plots: one with axis 1 vs axis 2, one with axis 2 vs axis 3, and one with axis 1 vs axis 3. When inputting my code, I only end up with one diagram and when inputting mdsg.mds$dims, the program returns 2 for 2 dimensions. How can I create the other two plots? Any help would be greatly appreciated, Calla Carbone The table I use is number of each taxa on each

Dear R-Listers, to measure the psychometric curve of pitch discrimination, one sequentially presents two tones of slightly different pitch to an observer (animal will do), and asks "which is higher". The pschometric curve is the fraction of correct responses plotted against the pitch difference. It passes through 50% (pure guessing) at zero and normally approaches 100% at large

I'd like to estimate an ordinal logistic regression with a random effect for a grouping variable. I do not find a pre-packaged algorithm for this. I've found methods glmmML (package: glmmML) and lmer (package: lme4) both work fine with dichotomous dependent variables. I'd like a model similar to polr (package: MASS) or lrm (package: Design) that allows random effects. I was

Hi, I want to fit some psychophysical data with cumulative gaussians. There is quite a convenient toolbox for matlab called 'psignifit' (formerly known as 'psychofit'). It allows the lower bound of the sigmoid to vary slightly from zero, aswell as the upper bound to vary from one. with these two free parameters, the fitted function is less sensitive to noisy data and outliers.

I don't think it is necessary to put binary versions of the Darwin/X11 version on CRAN any more. The current sources compile without problems on both Mac OS X 10.1 and 10.2, using either gcc/g77 2.95.2 or gcc/g77 3.1, or f2c. It seems to me that if you are using R from the command line, using X11, that you are sophisticated enough to install the tools below. And, if you want to install and

homals-0.9.0 is on CRAN -- by Jan de Leeuw and Patrick Mair This package implements the methods discussed in Gifi, Nonlinear Multivariate Analysis, Wiley, 1990. In the Gifi terminology it covers homals, princals, canals, morals, criminals, and overals. The R implementation fills several gaps in Gifi, adding multiple ordinal, numerical, and polynomial data transformations. Differences with