Appendix C - Blossom Development and Testing

We consider Blossom to be a platform for supporting research into various statistical concepts. It provides for data access and display of results for statistical functions we are investigating. We don't consider it to be a general purpose statistical package, nor do we make any assertions about its ease of use or efficacy for statistical computing.

Blossom is written in Fortran. The current version is in Fortran 95, using the Lahey/Fujitsu LF95 Version 7.1.2 compiler (Win32 Professional Language System), from Lahey Computer Systems, Inc.

Blossom access to Microsoft Windows is made possible with the Winteracter Fortran 9x GUI Toolset from Interactive Software Services, Ltd.

Blossom can use either of two pseudo random number generators (PRNG). By default the PRNG used in Blossom is provided by the Lahey/Fujitsu Fortran compiler. This pseudorandom number generator technology is based on Lehmer's pure multiplicative congruential algorithm (Dyadkin and Hamiltion 1997). Alternatively, upon user specification, Blossom uses the Mersenne Twister (MT) PRNG (Matsumoto and Nishimura 1998). Matsumoto and Nishimura describe Mersenne Twister as a twisted generalized feedback shift register sequence (TGFSR) algorithm.

Hundreds of hours of testing have gone into this (and previous) version of Blossom since development was initiated in 1989. We have done everything possible to ensure that our modifications of the principal computing routines for the MRPP family of statistics obtained from Paul. W. Mielke, Jr., yield numerical results identical to the original routines. We made comparisons with published and other known results, and had Dr. Mielke compare some of his original analyses with our program. Similar comparisons of numerical output were made for the regression quantile and rank score tests made with programs provided by Roger Koenker. No doubt, some errors remain undetected and we urge you to report any obvious or suspicious errors to us. The README file provides a list of pertinent information to provide us in an error report. We recommend running analyses on the datasets provided with the Blossom software to see if your computer duplicates the output in the User Manual and output files.

The Blossom software we provide has been scanned for computer viruses using the latest versions of Symantec anti-virus scanning programs. As far as we are able to determine, Blossom software as distributed from us is virus-free and there are no malware components. Blossom is not, we are sure, free of bugs. The authors welcome reports of errors.