Programmer’s Almanac

[edit] π-day

Today is π-day, because of the approximation 3.14. It seems that the holiday had not, unfortunately, been invented in 1592.

Wikipedia lists a few other days that approximate π:

• April 26 (when the distance of the Earth's orbit divided by the time it has traveled so far is equal to pi; on leap years the 25th)
• July 22 (22/7 in some date formats, a popular approximation of pi)
• November 10 (the 314th day of the year; on leap years the 9th)
• December 21, 1:13 p.m. (the 355th day of the year, celebrated at 1:13 for the Chinese approximation 355/113)

Here is a short program for calculating π in the language J, a variant of APL invented by Kenneth Iverson:

pi=: [: ": [: <.@o. 10x"_^] ,

[edit] Jonathan Bowen

Today is the birthday of computer scientist, Jonathan Bowen (b. 1956), whose interests include online museums such as the Museum of Computing. From a technical standpoint, Dr. Bowen serves as the chair of of Z User Group, promoting Z-Notation for formally describing computer-base systems.

[edit] Albert Einstein

And finally, today in 1879, Albert Einstein was born.

^{© 2007, Jorge Monasterio}