What's New - August, 2012
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August 3, 2012:
A user found an actual application
for what I thought was just an interesting mathematical exercise:
measuring the smallest circle which will cover a given set of randomly placed
dots. The application's objective is to measure the minimal circle
covering the placement of a group of projectiles fired at the center of a
target. In this case, the projectiles were "cutting slugs" designed to
punch holes in the target. If you are designing the tool to fire these
slugs, maximizing the accuracy is an important parameter and, if the targets
happen to be potentially explosive devices, maximizing the range while
maintaining acceptable accuracy might be even more important!
Circle Covering Points, Version
3.2 provides 3 decimal digit accuracy for data points entered. Hope
that accurate enough Mickey - I'll stick to programming!
August 5, 2012: Time to squeeze one more program before the real world takes over for the next week or so. Here is a Beginners level, Shuffle Demo program in the Delphi Techniques section. It takes less than 50 lines of user code to simulate "dealing hands" from a "deck" of numbers thanks to our 10 line "Shuffle" procedure!
August 12, 2012: Library unit UBigIntsV3 performs operations on arbitrarily large integers and includes an "IsProbablyPrime" function which implements the Miller-Rabin primality test . The unit resides in our DFFLibV14 library file, reposted today with a small correction to the function which fixes a potential memory leak under some conditions when temporary memory fields were not released.
August 18, 2012: We had a rewarding trip to Johnson City, Tennessee this past week to attend the "White Coat" ceremony for our granddaughter and 78 other bright college graduates beginning their 4 year journey through the School of Pharmacy at Eastern Tennessee State University. I was impressed by the school and its staff and learned more than I had imagined about what a Pharmacist is and does. Apparently they do much more than count pills! I look forward to learning even more over the coming years.
In the meantime, I also learned this week that there are 44,860 ways to arrange the digits from 1 to 9 into a set of prime numbers ranging from the smallest set with two primes {2, 14567389} to the largest set of with six primes, {2,5,7,43,61,89} . Here is Primes From Digits written primarily as a coding exercise. In the process of coding this solution, I spent too long tracking down the routine which converts mouse clicks on a memo to the line number clicked. As a result, I coded and posted another little demo program, Memo Clicks to illustrate the process.
August 27, 2012: A new Utility program, Count Phrases, was posted today. As the name implies it counts occurrences of 2, 3, and 4 word sequences within a loaded text file. A developer had asked how to do this as an aid to an SEO (Search Engine Optimization) investigation he is undertaking. I do not anticipate personally using the program but others may find a use. It did provide an interesting few hours figuring out how to extend our Count Words program previously posted as a Beginners level program in the Delphi Techniques section of DFF.
August 29, 2012: A viewer recently reported an error in the Round procedure TBigFloat class in unit UBigFloatV3 which process arbitrarily large floating point numbers. Round takes a parameter specifying the number of digits to the right of the decimal point to retain when rounding. The previous version returned 0 when rounding any value between 0 and 1 to the nearest whole number ( i.e. requesting 0 digits to the right of the decimal point ), when it should have returned 1 for values between 0.5 and 1. It now does. Library unit DFFLibV14 has been re-posted today with the revised UBigFloatV3 unit.