Mathematical Modeling for the Macintosh
Did you ever
Well, now you don't have to.
- have to fit your data to a function that was not necessarily a straight line?
- believe that you already knew some/all of the model parameters?
- discover that the residuals were Laplacian, not Gaussian :-(
- wonder if the optimum fit were statistically acceptable?
- want the minimum average deviation instead of least-squares?
- desire robust confidence intervals for the fitted parameters?
- wish that you could make a picture of the result (see Example above) with one keystroke?
- need to find the distribution that best described a set of random variates?
- or prove that they were truly Gaussian? Uniform? Poisson? ...
- think that a combination of two distributions might be the real answer?
- try to find the formula for the mean, variance, mode, etc., of some density function?
- require millions of variates from a specified distribution?
- give up on any of these and settle for second-best?
Regress+ ("Regress_plus") can do all of that and more!
It sets a new standard -- unmatched in power, flexibility, and user-friendliness.
View an introductory
Tutorial (271 K), on modeling in general, or
download (1.4 MB) the complete, free package (stuffed and binhexed):
Note: You might need the latest
Stuffit Expander® freeware to extract Regress+.
Regress+ (2.5.3) Features
- Simple (univariate) mathematical modeling
-- deterministic (regression)
-- stochastic (random variates)
- Up to 2,147,483,647 points (minimum 7)
- Robust goodness-of-fit testing
- Bootstrap confidence intervals (90, 95, and 99 percent) for
-- stochastic-model goodness-of-fit metrics
- Bootstrap methodology (where appropriate):
-- BCa technique (state-of-the-art)
-- percentile technique
-- tunable precision
- Optional "freezing" of initial estimate(s) for any parameter(s)
- Choice of optimization criterion
- No hidden assumptions anywhere:
-- no approximations, apart from those common to sampling and bootstrapping generally
-- no data transformations of any kind
- "Smart" dialogs to run unattended and/or in the background
- Textfile input (may contain unlimited comments)
- Both text and graphical output
- One keystroke makes a plot (may be saved as a PICT)
- Extensive documentation (in PDF):
-- Tutorial (50 pp.)
-- Users' Guide (36 pp.)
-- Technical Details and References (8 pp.)
-- Appendix A:
A Compendium of Common Probability Distributions (120 pp., separate volume)
-- Appendix B: Error Messages (4 pp.)
- Lots of sample datafiles
- Models: y = f(x), with 1 to 10 parameters
-- 22 Built-in families of models
-- Gaussian-Lorentzian model for spectral peaks (see Example #5)
-- "User-defined" model
- Special Simulated Annealing mode to help find initial parameter estimates
- Optimization criteria:
-- Minimum average deviation
- [Optional] Weights (for the dependent variable, y)
- [Optional] Listing of fitted data and residuals
- 56 Built-in distributions:
-- 30 Continuous
-- 17 Continuous binary mixtures
-- 5 Discrete
-- 4 Discrete binary mixtures
- Optimization criteria:
-- Maximum-likelihood (all)
-- Minimum Kolmogorov-Smirnov statistic (continuous variates)
-- Minimum Chi-square (discrete variates)
- [Optional] Discrete input may be grouped
- [Optional] Creation of samples of random variates (textfiles, see Example #10)
- Regress+ 2.5 runs on any PPC Macintosh under either
OS 9 plus CarbonLib (1.4 or greater)
- It will also run on any Intel Mac provided that Rosetta is installed. Starting with OS 10.6 (Snow Leopard), this is an Optional install that must be done manually. [See Coming Attractions, below.]
- For older platforms,
Regress+ 2.3.1 (1.5 Meg download) is still available.
- Regress+ 2.7 is under development for Snow Leopard and above. It has some new features and is much, much faster.
- It will also be accompanied by a new, improved
Who Uses Regress+ ?
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