kr=: [: ,./^:2 *"0 2 a kr b 2 2 2 3 3 3 2 4 2 3 6 3 2 2 2 3 3 3 5 5 5 7 7 7 5 10 5 7 14 7 5 5 5 7 7 7
On Sat, Oct 14, 2017 at 8:25 AM, Cliff Reiter <[email protected]> wrote: > The idea is to write a verb which gives the Kronecker product. > https://en.wikipedia.org/wiki/Kronecker_product > For example: > ]a=:2 2$2 3 5 7 > 2 3 > 5 7 > ]b=:1+4=i.3 3 > 1 1 1 > 1 2 1 > 1 1 1 > a kr b > 2 2 2 3 3 3 > 2 4 2 3 6 3 > 2 2 2 3 3 3 > 5 5 5 7 7 7 > 5 10 5 7 14 7 > 5 5 5 7 7 7 > > Note each entry in a times b appears as a block in the Kronecker product. > This may have been discussed in this forum before, but let's try to > rethink the problem. > > The first time I was challenged with this question was in June of 1999 at > a "J in the Math classroom" workshop at Messiah College. My (possibly > faulty) recollection was that their were four established Jers there (Ken > Iverson, Richard Brown, Donald McIntyre?? and myself). We investigated > defining kr. We each had a laptop, sitting in the 4 chairs in the picture: > http://webbox.lafayette.edu/~reiterc/j/ke_iverson/wdsc00017.jpg > It was revolutionary for the era that we were computing, but we were not > in a laboratory. > Happy Jing, > Cliff > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
