Unforgettable Numbers
Professor Kip Murray asked on the J Forum for the “unforgettable” times seen on a 24-hour digital clock. The problem is that every number has something notable about it, so that each number is “unforgettable” and consequently it’s hard to remember any single one of them. 0000 all zeros 0001 first counting number 0002 first […]
Foo, Shmoo
“We do not realize what tremendous power the structure of an habitual language has. It is not an exaggeration to say that it enslaves us through the mechanism of s[emantic] r[eactions] and that the structure which a language exhibits, and impresses upon us unconsciously, is automatically projected upon the world around us.” —Korzybski (1930) in […]
What's Your Favourite Beautiful Squiggle?
Roger’s post speculating on Ken Iverson’s favourite APL expression reminded me that one of the delegates at Dyalog ’14 conducted a quick survey to find the most popular primitive (thanks to Alex Weiner for taking the initiative here!). His findings are reproduced below: 9 votes: ⍴ 8 votes: ⍳ 6 votes: ⍨ 4 votes: ⍠ […]
Ken Iverson's Favourite APL Expression?
What was Ken Iverson’s favourite APL expression? I don’t know that he had one and if he had I don’t know what it was, but if I have to guess … From Sixteen APL Amuse-Bouches: The expression (0,x)+(x,0) or its commute, which generates the next set of binomial coefficients, is present in the document that […]
Musings on Reduction
In one man’s humble opinion, reduction (⌿) is the Queen of Operators. Each (¨) comes a close second, but doesn’t get the cigar because each can be written in terms of reduction. Two special cases are of interest: reduction along axes of length 1 (or reduction of a scalar) and reduction along axes of length […]
