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
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