HOF: Fitting Huisman-Olff-Fresco models with maximum likelihood

I have recommend HOF models as an alternative to analyse whether species responses are significantly skewed along gradients (Journal of Vegetation Science 8, 147-152; 1997: abstract). I have now developed a program for Maximum Likelihood estimation (Poisson error) for HOF models. Data input is from CANOCO-formatted files, and output statistics use Deviance statistics (like GLIM). As a sample, here is a figure (gif, 14K) of diatom responses along alkalinity gradient with HOF models.

• I have moved my development work into R statistical environment. A brief introduction into fitting HOF models in R is available in a pdf document. Despite my earlier message on this page, I have started to develop the stand-alone hof program again. However, the upgraded versions are available for Linux only (I don't have an access to a Windows machine with development tools).
• I have started to develop an R package called `gravy' (gradient analysis of vegetation) which includes first version of HOF fitting. The package is still very preliminary and incomplete, and it is not for the faint at heart. You may check `gravy' among R packages at my software listing page (and pick the latest version).
• Download Linux binaries hof-2.3.8-1.i386.rpm (96K, 10 Jun 2002). The rpm files require Dislin graphics libraries to run; these can be downloaded free through Dislin homepage. I cannot make full source code available, since hof uses Numerical Recipes which cannot be distributed in source code. If you can help me to replace these routines (maximizing likelihood function with dfpmin.c and evaluating F and Chi-squared statistics) I will release the source code as well. The rpm files were built for Red Hat 7.1 and they are GPG signed. You should be able to get my public key at http://www.pgp.net/, ID 4F4D8DA5.
• DOS/Windows: Download hof.zip (executable, version 2.3, 16/10/98, 174K), read the manual of version 1 or the readme file of version 2.3.
• Citing my HOF software.