I have to determine such an F. F is not given. The only known information is how the values are ordered.
On Thu, Feb 25, 2010 at 4:44 PM, Henry Rich <[email protected]> wrote: > You are looking for a solution given any F? > > If F is [, no solution is possible. > > Henry Rich > > Yuvaraj Athur Raghuvir wrote: > > Dear J Forum, > > > > I have an interesting problem for which I need more insights to proceed. > > > > I have to determine three unknowns: > > (a) W where 2 = $W = w1, w2 > > (b) L where 3 = $ L = l1 , l2 , l3 > > (c) F a dyad that takes scalar inputs > > > > Such that > > (6 1 5 2 3 4) -: \:; L F"0 0/ W NB. the order of values is known. > > > > For example, > > F =: * > > (6 1 5 2 3 4) -: \:; L F"0 0/ W [W =. 3 9 [L =. 20 16 12 > > 0 > > > > I designed a test that is essentially a blind brute force on the inputs > > assuming F is given: > > F =: 4 : 'x^2 - y^2' NB. for example > > odometer =: #: i.@(*/) > > test =: 3 : 0 > > n =. y > > w =. odometer n,n > > l =. odometer n,n,n > > NB. I get a length error if I use bigger inputs. So chunking into 100's > > for_i. i. 100 %~ {. $l do. > > for_j. i. 100 %~ {. $w do. > > b =. ('' -: I. (6 1 5 2 3 4) -:"1 1 (>@[ \:@,"_1@:(F"0 0/"1 1) >@])/ > > (_100{.(100*>:i){. l);(_100{.(100*>:j){. w)) > > smoutput i,j > > if. b<1 do. break. [smoutput 'found it';i;j end. > > end. > > end. > > '' > > ) > > > > I am not convinced that I can find a solution this way since the > functional > > forms are far too many to be tried out notwithstanding my other > assumptions. > > > > > > Any suggestions? > > > > Regards, > > Yuva > > ---------------------------------------------------------------------- > > 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
