3. Public domain statistical software
�R� is an excellent freeware version of the commercial statistics package S (http://www.burns-stat.com/pages/Tutor.slanguage.html) and S-Plus (http://www.insightful.com/product/splus/default.asp). R provides routines for univariate statistics, multivariate statistics, graphics, time series, bootstrapping, regression, contingency table analysis and much more.
MacAnova is a free, noncommercial, interactive statistical analysis program for Windows, Macintosh and Unix. It has diverse capabilities, although not as broad as �R.� Its strengths are analysis of variance and related models, matrix algebra, time series analysis (time and frequency domain), and (to a lesser extent) uni- and multi-variate exploratory statistics. MacAnova has a functional/command oriented interface, with a language and syntax much like �S�, �S-Plus� or �R�.
Surfstat.australia is an online text in introductory statistics. SurfStat has statistical calculators that replace most tables of statistical distributions. Java applets are available for the normal, Student�s t, Chi-squared, and binomial distributions.
This site provides a very useful demonstration of sampling. It makes it relatively easy to explore sampling distributions and demonstrate the effect of sample size on the desired statistical estimates. It has useful statistical calculators that replace tables of critical values in statistical books. Includes sections on describing univariate and bivariate data, an introduction to probability, the normal distribution, sampling distributions, point estimation, confidence intervals, the logic of hypothesis testing, testing hypotheses with standard errors, power, analysis of variance, prediction, chi square, distribution-free tests, and measuring effect size.
The Vassar Stats web site for statistical computing is a potentially useful and user-friendly resource for performing statistical computations. It has several statistical calculators. Many basic concepts of statistics are covered, including an introduction to probability sampling distributions.
The Calcugator is a free calculator, a plotting engine, and a programming environment. As a calculator it is simple to use and has similar functionality as MATLAB. It offers close to 200 functions/operators to perform real, integer, rational, complex, boolean, statistical, vector, array and matrix computations. Both the input and output of the program are displayed on standard windows which can be further edited, saved, merged, print-previewed and printed. As a plotting engine it allows rapid creation of 2D plots of functions as well as polar and parametric displays. It also allows creating 3D plots of functions, contour plots and 3D parametric displays. The Calcugator has also functions to create bar, pie, pareto and xy charts. All plots can be configured using the mouse (zooming, panning, selecting). Titles and labels are supported. All figures created by the Calcugator can be exported into popular file formats or pasted into an editable window. As a programming environment it offers a computer language with identical syntax as that of Java/C/C++, without the need to compile user�s code. The creation of user-defined functions is natural and mimics the syntax used by a teacher on the blackboard. Languages include English, Italian, Portuguese, French.
ViSta constructs very-high-interaction, dynamic graphics that show you multiple views of your data simultaneously. The graphics are designed to augment your visual intuition so that you can better understand your data. ViSta's visually intuitive and computationally intensive approach to statistical data analysis is designed to clarify the meaning of data so that you can see what your data have to say. ViSta is free and open. It can be downloaded from the web. Platforms: ViSta runs under Windows, on Macintosh, and under Unix. ViSta is available in English, Français, and Español.