What's New -  March, 2011

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March 12, 2011:  GunPort Domino Puzzles Version 2 was posted today. The puzzle requires dominoes be placed on a board leaving the maximum number of empty surrounded single squares (the gun ports).  Version 2 adds program solution searching to the original version which allowed user searches only. It also allows board sizes from 3x3 to 12x12.   It's been a challenging, educational,  and satisfying 2 week project which has put me behind on a couple of other projects, but I could easily spend that much time again exploring ways to improve the search algorithm. Coming back to a spare computer and seeing a solution posted after 13 hours of run time was satisfying and fun! 

March 13, 2011: It didn't take long to produce the next Gunport's update .  Version 2.1 upgrades the LPSolve solver module from V5.1 to V5.5 which looks to be significant faster at finding solutions in the cases I've run so far.

 March 18, 2011:  The only problem with having users of my programs is that they keep finding bugs!.  Just kidding,  I enjoy fixing problems because each few minutes invested makes the program just a little bit better, permanently.    Maze, Version 3.2 fixes another path drawing problem,  and GunPorts Version 51.2 reverts back to LPSolve V5.1 due to problems with V5.5 and also adds user access to some additional options that I'm using to investigate solving times when the program is searching for solutions.     

March 21, 2011:  Our Reaction Times program has seen more use in educational environments than I could have imagined when I wrote it.  Originally intended as a Science Fair project for a granddaughter, it's been used in Statistics classes in California Community Colleges, by university students such as those mentioned in the February update  to help study response times of stroke victims at a Danish hospital. and most recently engineering students at the University of Singapore.  Reaction  Times Version 4 iincludes a new type of response:  JPEG images are displayed in a chosen sequence and detail records written for each image, even if the response was early or late.  This will let the team associate specific images with response times in their project about signage recognition.  There are also a few enhancements for the Danish guys to eliminate load time for a specific audio file  to see if their observed 40 ms lag between audible and visual stimuli is due to file load times.     

March 23, 2011:  Help!  I'm working on this program and just can't stop!  I decided to reorder the variables fed to LPSolve in GunPortsVersion 51.3, so the the Horizontal, Vertical, and Monomino binary variables for each cell are interlaced.   This has reduced solving time dramatically in most cases.  The 7x7 case is now solved in 3 seconds compared to 2 hours for the previous version.  The10x10 board search which previously ran for 49 hours before I stopped it, has not yet been rerun.   I am , however, proud to now include  an optimal 10x10 solution found  manually by overlapping a 4x10 solution whose last row pattern happened to match the top row pattern of a 7x10 solution.  "More than one way to skin a cat" as we say here!  

March 30, 2011:  I finally had a chance this past week to work on a "just for fun" project.  AlphabetGrid helps solve another puzzle from my 2011 Mensa 365 Brain Puzzlers Calendar. I posted it our Delphi Techniques section because it provides interesting examples of depth first searching, drawing on a grid, and generating non-uniform distributions.