What's New -  March, 2010

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March 28, 2009:

 

Pi is between 3.0 and 3.464
(but it gets better)!

 I spent most of this past week in discussions with Mr. Archimedes about his approximation of the value of Pi.  It was largely a one-way conversation with me asking "How do you know that?" and his only reply being the sparse text he wrote 22 centuries ago.  Fortunately we have an English translation of his  "The Measurement of the Circle" which largely presumes that you have recently completed your high school Algebra and Geometry classes.  There are many "proof is left to the user" results presented on the path to his novel, and most accurate at that time, conclusion that the ratio of the circumference to the diameter of a circle is greater than 310/71 and less than 31/7.  Did I mention that he did not have access to decimal notation or the trigonometric functions which depend on knowing the value of Pi or calculators or computers?  I have new appreciation for an amazing mind. My Archimedes' Estimation of Pi program is an attempt to follow and fill in some of the blanks in his proof.   
     

March 18, 2010:  I use our "Monitor Off" program each evening to blank the monitor on my old laptop dedicated to capturing and reporting outputs from our weather station.  Monitor Off Version 2 fixes a problem a user had with the alternative code for blanking the monitor, The "Power-Off" option, should now work when the "Standby" option does not.  I have tested it under Windows 7 on my  Dell Studio 17, my  first laptop to require its use.   The program uses the Pause key to blank the monitor, regardless of the active window.

In the process of testing, I also found that the Studio 17 uses the Fn + F12 keys to emulate the missing Pause key.  I have no experience with other company's laptops, but I suspect that they all use a similar technique to replace  the seldom used Pause key with a virtual alternative.  Dell doesn't seem to document the "feature", but my Key Codes program will help find the hidden key in short order.   

 

March 11, 2010: A small bug was reported and fixed in the Computational Geometry test program, Geometry4 today. The "Draw line from point perpendicular to line" demo page (PerpSheet) did not allow the initial line to be  drawn due to a rookie coding error.  In the "mouse move"  procedure, the statement:  if (activepage=PerpSheet) or (activepage=AngleSheet) and (dragval=1) then begin needed an extra set of parentheses (colored red here) to look like this: if ((activepage=PerpSheet) or (activepage=AngleSheet)) and (dragval=1) then begin. This is the coding equivalent of writing  the algebra expression A + B * C when you meant (A + B) * C.  Results in both cases were wrong!

March 4, 2010:  A Text Spinner program suggested by a viewer was added to our Delphi Techniques section. today.  A "text spinner" randomly changes the content of a text based on some criteria, in this case a supplied set of alternative phrases embedded within the input text.  Not very practical, but an interesting intermediate level programming exercise anyway.    

February 4, 2010:

W O R D
O B O E
R O B E
D E E D

Word squares are square letter arrays with rows containing words which match words formed by the corresponding columns. Here is a Word Square Search program which searches a 62,000 word dictionary to create word squares based on an initial word provided by the user.   At left is one of 149 solutions found for the word "WORD".
.  

February 1, 2010:   A couple of times each year I get a request for help from a student requesting help in some project using my Reaction Times programs.  This year it was a graduate student in at a Medical School in Ecuador whose thesis topic is to test the effect of sleep deprivation on interns as result of the long hours they put in.  Her problem turned out to be decimal separator confusion because the PC she was using happened to have the Window's Locale set for a European country.  Changing back to Ecuador set it from comma back to dot and allowed her to analyze her data.  While investigating, I discovered and fixed a problem with the ResponseStats statistical analysis  program that kept a newly loaded response statistics file from being made available.  Reaction Times programs including ResponseStats Version 3.1 was uploaded today to fix the problem.

 


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