Thank you, Henry. While I try to translate a mathematical expression into a J expression, I often discover hidden patterns in the expression with great joy. It sometimes leads me to a path to new insights.
It's the reason I am looking for the shortest form this time. 2007/6/26, Henry Rich <[EMAIL PROTECTED]>:
Not really, but gee, shouldn't we be using our wonderful language to provide the most expressive form of c rather than just the shortest? a =. (# * +/)@:* - *&(+/) c =. a % [EMAIL PROTECTED] %:@* [EMAIL PROTECTED] 1 3 2 4 c 2 4 3 3.5 0.831522 a =. ((# * +/)@:* - *&(+/)) "1 c =. %: @ (%~/ . *) @: (a/~) @: ,: 1 3 2 4 c 2 4 3 3.5 0.831522 I don't think either of these forms is useful for real work, since they involve subtracting big near-equal numbers, but I learned something about the computation by writing them. Henry Rich > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of June Kim > Sent: Tuesday, June 26, 2007 10:08 AM > To: Programming forum > Subject: [Jprogramming] Correlation Coefficient > > I've been playing with the expression at > http://en.wikipedia.org/wiki/Correlation > > > c=.(*&[EMAIL PROTECTED]@:*)%*&(s(-~(#*s=.+/))&.:*:]) > 1 3 2 4 c 2 4 3 3.5 > 0.831522 > > c is as short as I can get. Could you come up with a verb for > correlation, shorter than c? > ---------------------------------------------------------------------- > 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
