Another example: (_1 4 5; 1 0 ; 2) |: y
Axis 2 is moved to the back; axes 1 and 0 are run together and moved to be in front of that (the effect would have been the same for 0 1 instead of 1 0); axes _1, 4, and 5 are run together and moved to be in front of that; and any remaining axes are moved to be in front of that. Dyadic transpose has been famously inscrutable since the days of APL\360. ----- Original Message ----- From: Roger Hui <[EMAIL PROTECTED]> Date: Friday, January 5, 2007 9:54 pm Subject: Re: [Jprogramming] Dyadic Transpose > No, it's correct as written: 2 and 3 are moved > to the front. Successive opened atoms of x > specify axes to be moved to the tail, but since > in the example no more axes remain after > 0 1 and 2 3, 2 3 are in effect moved to the front. > ----- Original Message ----- > From: June Kim <[EMAIL PROTECTED]> > Date: Friday, January 5, 2007 9:43 pm > Subject: Re: [Jprogramming] Dyadic Transpose > > > 2007/1/6, Roger Hui <[EMAIL PROTECTED]>: > > > Yes: > > > > > > (2 3;0 1) |: i.2 3 4 5 > > > 0 80 > > > 6 86 > > > 12 92 > > > 18 98 > > > > > > Run axes 2 and 3 together and move to the front, > > > > I"m a bit confused. Shouldn't it be instead "move to the tail"? > > > > "x|:y moves axes x to the tail end." > > > > $(0 1 ) |: i. 2 3 4 5 > > 4 5 2 3 > > > > > and run axes 0 and 1 together. i.e. z[i;j] = y[j;j;i;i] > > > > Thank you. That expression is very helpful to understanding. > > > > > > > > See also: > > > http://www.jsoftware.com/jwiki/Essays/Transpose ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
