Site index

Web page with a revamped version of the software for fitting height-age/site index models with the methods described in my Biometrics article.

Automatic differentiation

For a short description and a compiled MS-DOS version of GRAD, the program discussed in my Automatic Differentiation paper, look here. You can also download from the SimTel archives, or from any of its mirrors under msdos/math/, or search for grad with Archie.

3D Viewer

The "3d-viewer" program has been around in the public domain for a while. It shows 3-d wire frame data on PCs, with real-time rotation under mouse control. Data is read from simple ASCII files. The distribution package contains an example of pine branches from work done with David Whitehead at FRI. It is also useful for visualizing 3-d statistical data, etc. Shows its age, hardly flash interfaces and cutting-edge technology, but still does the job. Available in SimTel and mirrors in msdos/graphics/ More.

Weibull fitting

Method-of-moments method, with a shortcut.  Here is a short text file with some notes and source code in Basic, C, and Pascal.  Or try this applet.  Or an Excel add-in (works also in OpenOffice).

For R, source or copy and paste this.

But before you get carried away fitting distributions to tree size data, see items [23] and [49] here.

Growth models

A simple compiled MS-DOS Basic implementation of the Golden Downs radiata pine model (zip, 30 KB).

Another no-frills PC simulator, compiled APL, for eucalypts in Chile (in Spanish, zip, 292 Kb.)

TADAM: growth models for Douglas-fir, lodgepole pine, spruce.

Scube, growth model for interior spruce. LobDyn for loblolly pine. TAG for aspen. Site index models.

Growth-curve Explorer

Java applet showing off a generalized growth curve equation.

Top height calculations

R code for estimating top heights from sample plot data.  Copy and paste in R, or modify for other languages.  See publication [41].


IFS, the original. Primitive user interface by today standards, but may have some historic interest (or even be useful, I understand that it is still used in places.) This demo version (zip, 49 Kb) was compiled for MS-DOS, and crippled by allowing no more than 4 crop types. If I ever find the earlier code that was offered for free with the paper I would put it here. All singing and dancing descendant can be bought from Forest Research (no commission, no royalties, no recommendation, no responsibility!)

Some old Open Days demos (zip, 96 Kb, with English and Spanish versions).

Applet showing relationship between MAI and CAI.

File translated from TEX by TTH, version 2.00.
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