mf1=: (-@(*./)@(1&=) ^ #) @ {: @ (__&q:)
----- Original Message -----
From: Roger Hui <[EMAIL PROTECTED]>
Date: Monday, September 17, 2007 10:16
Subject: Re: [Jprogramming] Mobius function
To: Programming forum <[email protected]>
> mf=: (*./@(1&=) * _1 ^ #) @ {: @ (__&q:)
> (mf -: mobiusT)"0 >: i.16
> 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
>
>
>
> ----- Original Message -----
> From: Arie Groeneveld <[EMAIL PROTECTED]>
> Date: Monday, September 17, 2007 9:58
> Subject: [Jprogramming] Mobius function
> To: Programming forum <[email protected]>
>
> >
> > Exercising on tacit verbs I succeed to define
> > the Mobius function.
> >
> >
> > Explicit version:
> >
> > mobiusX=: 3 : 0
> > ms=.{:__ q: y
> > if. 0=+/1<ms do. _1^+/ms else. 0 end.
> > )
> >
> > mobiusX"0 [1+i.16
> > 1 _1 _1 0 _1 1 _1 0 0 1 _1 0 _1 1 1 0
> >
> >
> > Tacit version
> >
> >
> > mobiusT=: [: 0: ` (_1^#) @. (0= [:+/1<]) [: {: __ q: ]
> >
> > For the value of mobius N = (-1)^r in case N is the product
> > of r different primes, one may use (_1^#) or (_1^+/) because
> > in this case they are equivalent:
> > - determining the length of the list of exponents
> > - summing the one's of the exponents.
> > It's also very convenient that they both handle the special
> > case for mobius 1 = 1.
> > In case mobius N is not square free the result has to be 0,
> > so I have to use the constant function 0:.
> >
> >
> > mobiusT"0 [1+i.16
> > 1 _1 _1 0 _1 1 _1 0 0 1 _1 0 _1 1 1 0
> >
> >
> >
> >
> >
> > a.{~q:9991
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