Too fast. Does not allow ni=0. R.E. Boss
-----Oorspronkelijk bericht----- Van: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Namens R.E. Boss Verzonden: dinsdag 31 oktober 2006 15:08 Aan: 'Programming forum' Onderwerp: RE: [Jprogramming] Boxing according to a Pattern BoxAcc=: <;.1~ [:([EMAIL PROTECTED]: e.])[:+/\0&, X=i.10 and P= 1 2 3 4 then (i.10)(<;.1~ [:([EMAIL PROTECTED]: e.])[:+/\0&,)1 2 3 4 +-+---+-----+-------+ |0|1 2|3 4 5|6 7 8 9| +-+---+-----+-------+ R.E. Boss -----Oorspronkelijk bericht----- Van: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Namens Leigh J. Halliwell Verzonden: dinsdag 31 oktober 2006 13:39 Aan: 'Programming forum' Onderwerp: [Jprogramming] Boxing according to a Pattern Dear J Forum: Given a vector X of n atoms, and a partition P of non-negative integers that sum to n; i.e. n = n1+n2+...+nk, how can I efficiently create a list of k items, whose first atom is the box of the first n1 elements of X, whose second atom is the box of the next n2 elements, etc? Empty boxes (ni=0) must be allowed. I can do this with difficulty; but I suppose that J primitives allow it to be done as a one-line tacit dyadic function X BoxAccTo P. Thanks. Sincerely, Leigh ---------------------------------------------------------------------- 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
