I20a=: #: @ (2&^) @ i. @ - which can be shortened to [: #: 2 ^ i. @ -
was in the link I provided. Still longer. R.E. Boss > -----Oorspronkelijk bericht----- > Van: [email protected] [mailto:programming- > [email protected]] Namens Don Guinn > Verzonden: dinsdag 24 augustus 2010 14:31 > Aan: Programming forum > Onderwerp: Re: [Jprogramming] Creating a matrix (some polish required) > > > ([: #: 2 ^ i.)_4 > 1 0 0 0 > 0 1 0 0 > 0 0 1 0 > 0 0 0 1 > > > On Tue, Aug 24, 2010 at 7:23 AM, Alex Gian > <[email protected]>wrote: > > > Square it and you have a 35th way to make an identity matrix! LOL. > > > > > > On Tue, 2010-08-24 at 14:07 +0200, R.E. Boss wrote: > > > ([: #: 2 ^ i.)4 > > > 0 0 0 1 > > > 0 0 1 0 > > > 0 1 0 0 > > > 1 0 0 0 > > > > > > Is this one of the few(?) occasions where generating the 'anti > identity' > > is > > > shorter than the main identity? > > > c.f. > > > > > > http://www.jsoftware.com/jwiki/Essays/Identity%20Matrix#BinaryRepresentati > on > > > > > > > > > R.E. Boss > > > > > > > > > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
