OpenEuphoria

Re: math combinations

• Posted by tone.skoda at siol.net May 27, 2002
• 448 views

Thanks! You saved me a lot of trouble, I was going to use it for sequences.

----- Original Message -----
From: <Henri.Goffin at sbs.be>
To: "EUforum" <EUforum at topica.com>
Subject: RE: math combinations


>
> There is a little weakness in the Permutation function in R. Forno's
Genfunc.e.
> It does not correctly manage a sequence that contains sequences as
elements.
> You can convince yourself with the following:
> ------------------------------------------
> include genfunc.e
> sequence S
> S = {{1},2,{3,4}}
> for i = 1 to 6 do -- 6 = 3! (factorial, the number of permutations of 3
objects)
> ?Permutation(S,length(S),i)
> end for
> ----------------------------------------
> But the correction seems straightforward.
> In genfunc.e (version 1.3) on line 2072, replace:
>     return set[a] & Permutation(set[1..a-1] & set[a+1..len], size - 1,
which)
> with:
>     return {set[a]} & Permutation(set[1..a-1] & set[a+1..len], size - 1,
which)
>
>
> Have a nice day, all.
>
> Henri Goffin
>
> > -----Original Message-----
> > From: tone.skoda at siol.net [SMTP:tone.skoda at siol.net]
> > Sent: 27 May, 2002 05:49
> > To: EUforum
> > Subject: Re: math combinations
> >
> >
> > I figured it out now after I searched mailing list archives.
> >
> > for i = 1 to 10 do
> >     ?  Permutation({1, 2, 3}, 3, i)
> > end for
> >
> > Still an example for every function would be very nice.
> >
> > ----- Original Message -----
> > From: <tone.skoda at siol.net>
> > To: "EUforum" <EUforum at topica.com>
> > Sent: Monday, May 27, 2002 5:01 AM
> > Subject: Re: math combinations
> >
> >
> > >
> > > Thanks, but I really don't know how to use that function.
> > > It would       help   if it had examples cause with examples you can
see
> > the
> > > most clear what something does.
> > >
> > > Here it is with all its documentation:
> > >
> > > Permutation(sequence set, integer size, integer which)
> > > --Returns a sequence containing the permutation with size 'size',
> > > -- numbered 'which', from the set 'set'.
> > > --The set is any sequence of objects, and so is the result.
> > > --'which' starts at 1 and goes to the number of existing permutations
> > > -- of this size.
> > > --In case 'which' is out of bounds, an atom containing -1 is returned.
> > >
> > > ----- Original Message -----
> > > From: "Derek Parnell" <Derek.Parnell at SYD.RABOBANK.COM>
> > > To: "EUforum" <EUforum at topica.com>
> > > Sent: Monday, May 27, 2002 4:13 AM
> > > Subject: RE: math combinations
> > >
> > >
> > > >
> > > > Have a look at Ricardo Forno's general utility package in th
> > contributions
> > > > page. It has a Permutations function in it which sounds like it
might
> > work
> > > > for you.
> > > >
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> > > >
>
>
>