Reviewed by
(? 1996, Dylan Bulseco. All rights reserved)
(Issue 2; posted February 20, 1997; archived March 6)
Introduction
How does one pick the perfect data analysis software package for Windows? Since the "perfect" package probably does not exist, picking the best program for one's needs is the next best bet. This review provides a few insights about some of the data analysis and graphical presentation packages available for Microsoft Windows; it will not consider general spreadsheet programs such as Excel. The packages reviewed are:
Prices range from $199 (DeltaGraph) to $495 (GraphPad Prism, Origin and SigmaPlot); see purchasing information in the individual reviews.
These programs have a few basic features in common:
In addition, a few of these programs include built-in programming or scripting languages, and allow enhanced data analysis routines through access of external DLLs provided by the user.
Although the myriad of choices is perplexing, data analysis using Windows programs has never been better. Many of these products have gone through several revisions, each improving on the interface as well as implementing powerful mathematical features. Fast Fourier Transforms, Savitzky-Golay smoothing functions, numerous statistical tests (both parametric and nonparametric) and peak integration are common features of most of these programs. In addition, nonlinear curve fitting can be achieved using Simplex, Powell's, or Marquardt-Levenberg algorithms, with built-in or user-defined equations. All of the programs use excellent graphical interfaces built around standard Windows menus, providing the user with complete control over the presentation of results in graphs or tables.
How Do They Stack Up? (see tabular comparison of features)
Picking the right software is no easy task. Besides considering features, one must also evaluate the practical usability of these features. In my opinion, if you are still running Windows 3.1x on a 486-based machine, GraphPad Prism and Origin from Microcal Software offer the only software solutions for their powerful data analysis features; ease of use; and stable, intuitive interfaces. While Prism offers lots of intelligent features and automates many aspects of data analysis, it lacks flexibility and some of the more advanced data manipulation tools. Origin, on the other hand, is very easy for the novice user, yet offers much power and flexibility through LabTalk, the built-in scripting language. If mathematical-intensive analysis is needed, and plotting is of secondary concern, Scientist for Windows may be a viable option. In addition, both Scientist and Origin allow users to access external DLLs for added options and flexibility during routine data analysis.
If the hardware you have is adequate to run Windows 95 or Windows NT, GraphPad Prism, Microcal's Origin, and Jandel's SigmaPlot offer superior data analysis features in solid, well-designed software packages. If price is the primary consideration, PSI-Plot offers the best deal, but you must sacrifice the benefits of well-documented packages such as Prism, Origin, and SigmaPlot.
Evaluating this Evaluation
This evaluation has omitted many excellent programs, including Fig P and Axum. More information on these programs can be found on the WWW by following the links. In addition, several programs with command-line Windows interfaces (e.g., MLAB, and S-PLUS) accomplish similar analyses, but require a greater time investment to learn.
In an effort to evaluate the latest versions of these programs, some 32-bit packages (SigmaPlot, PSI Plot, and DeltaGraph) have been compared to their 16-bit (Prism, Origin, Scientist) competitors. Because all were evaluated on a 486-DX2/66 machine running DOS 6.2 and 16-bit Windows 3.11, Win32s extensions were required to run the 32-bit programs. In addition, all products were evaluated on a Pentium 120 machine running Windows 95, enabling me to assess the native 32-bit applications in a 32-bit operating system.
Finally, visit my Web page for additional information on nonlinear curve fitting using these and other Windows data analysis programs, as well as a few tricks on implementing global nonlinear curve fitting.
Comparison of FeaturesDylan Bulseco is Research Associate at the Worcester Foundation for Biomedical Research.
