What's New - August 2001

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August 31, 2001: 
A Delphi Topics page was posted a while back showing how to sort a StringGrid on any column.   The simple sort used there was fine for a demo with a few rows - not so good when I tried it on a 10,000 row grid recently.  Here's a page with a StringGrid version that will do the job in a few seconds instead of minutes or hours.  The application, by the way, is a booklist browser for the Accelerated Reader program used in a number of schools these days (including  the school of one of my three  precocious [and precious] granddaughters).   A Web-based version is next -  I'll keep you posted.    

August 30, 2001:  I'm back!  Two more weeks of entertaining grandkids was time well spent.   But they're all back in school now, so I guess it's time for me to get back to work too.    I just saw that Borland is offering a free download of Delphi 6 Personal!, in exchange for answering some survey questions - sounds like a fair exchange to me.   Not surprisingly, the actual download link seems to be overloaded right now - but sometime in the next week or two you should be able to get a copy.   Be warned, it looks like it's a 140mb download.

August 14:2001:   I replaced version 1 of Peg Solitaire with version 2 - the user can actually make moves and try to solve the puzzles now.      For programmers - standard drag cursors have been by customized versions.  Creating customized cursors is  worthy of a Delphi-Techniques page.   Stay tuned.    

 By the way, Plus and Cross are the names of two of the solitaire board configurations solved here - which reminds me of a story about the youngster who was getting poor grades in mathematics.   His parents finally transferred him to a Catholic school and saw his math grades go to straight A's .  When asked what triggered the improvement, the boy said "When I walked in the first day and saw that guy nailed to the plus sign, I knew  they were really serious about math and it was time to shape up!'             

Diamond

Fireplace

August 10, 2001:  Here's version 1 of a   Peg Solitaire game.   I guess this version, in which the program does all of solving isn't exactly a game.  More an example of the power of a simple depth first search to solve a problem.    We can search about half a million board positions per second and surprisingly  the typical problem is solved in only a couple of million position searches.   Surprising because the number of board potential positions even for "Fireplace" is around 40 million and for "Diamond"  is around 1027.    Fortunately the number of positions actually reachable seems to be much smaller.    Those two configurations are among the seven common initial configurations solved  by this version.   Oh yeah, there's also an animated playback of the solution once we find it.  

In case you're not familiar with the game, the objective is to remove pegs by jumping them with another peg until the last peg is left in the center hole.

 Version 2 with user play, (more fun for the user, but less fun for the programmer) will be along shortly.   

 

August 6, 2001:  Fibonacci was probably the greatest mathematician of the 13th century - his works were instrumental in converting Europe from the Roman numbers to the Hindu-Arabic system.  His name is most commonly associated with the  series of numbers formed by starting with 0 and 1 and then creating the rest of the series by adding the two prior members.   What's amazing is that  this series approximates the Golden ratio which  frequently appears in nature including the arrangement of seeds in sunflower heads.  (In the image at left the apparent overlapping seed spirals have 34 arms in one direction and 55 in the other, the 10th and 11th Fibonacci numbers.)   Here's  more of  the story and a simple Delphi program that draws Fibonacci Sunflowers.