search for: polyr

A bit late, but you might like to look at http://www.qimr.edu.au/davidD/polyr.R Regarding the original posters queries: You can analyse polychoric correlations as if they were Pearson correlations using standard software (eg sem), and this usually doesn't do too badly, or go to AWLS (Browne) in LISREL etc, or ML analysis of the full multidimensional contingency table u...

This is a bit late, but: > About two years ago there was a thread about this which suggested that at > that time nobody had these coefficients ready to go. > (a) has anyone in the meanwhile programmed them? http://www.qimr.edu.au/davidD/R/polyr.R > (d) I appreciate this last item is not strictly an R question, but my > intention is to use these as input into the sem package for structural > equation models. If anyone thinks that is misguided I would be intersted to > here. > > Michael Dewey > m.dewey at iop.kcl.ac.uk...

Hello, I am struggling to figure out how to analyse a dataset I have inherited (please note this was conducted some time ago, so the data is as it is, and I know it isn't perfect!). A brief description of the experiment follows: Pots of grass were grown in 1l pots of standad potting medium for 1 month with a regular light and watering regime. At this point they were randomly given 1l of one