a 0 0 1 1 1 1 2 2 2 2 2 4 4 4 5 5 b 5 0 7 8 9 2 2 5 5 5 3 8 0 0 5 6 a </. b ┌───┬───────┬─────────┬─────┬───┐ │5 0│7 8 9 2│2 5 5 5 3│8 0 0│5 6│ └───┴───────┴─────────┴─────┴───┘
2012/1/10 Ben Gorte - LR <b.g.h.go...@tudelft.nl> > Dear Forum, > > Perhaps it is a beginners question, but somehow I cannot come up with a > decent answer. > > I have a matrix like of position-value pairs like: > > 0 0 1 1 1 1 2 2 2 2 2 4 4 4 5 5 > 5 0 7 8 9 2 2 5 5 5 3 8 0 0 5 6 > > (it could also be transposed), and I would like to have a list of boxes: > > +---+-------+---------++-----+---+ > |5 0|7 8 9 2|2 5 5 5 3||8 0 0|5 6| > +---+-------+---------++-----+---+ > > So the values are placed in boxes according to the positions. > > My matrix above is sorted (from left to right), but probably this is not > essential for most solutions. Furthermore, the order of the elements within > the boxes of the result is not important for the remainder of my algorithm. > > I have a solution that loops through the matrix from left to right, but it > is way too slow (and it does not look like J). Isn't there a better way? > > Thanks, > Ben > > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
