Re: Re: Eliminating Annoying Minus Signs
- To: mathgroup at smc.vnet.net
- Subject: [mg58780] Re: [mg58770] Re: [mg58756] Eliminating Annoying Minus Signs
- From: yehuda ben-shimol <bsyehuda at gmail.com>
- Date: Mon, 18 Jul 2005 03:21:18 -0400 (EDT)
- References: <20050717191307.ZPJB19733.lakermmtao05.cox.net@smtp.east.cox.net>
- Reply-to: yehuda ben-shimol <bsyehuda at gmail.com>
- Sender: owner-wri-mathgroup at wolfram.com
correct,
thanks for the correction.
yehuda
On 7/17/05, Bob Hanlon <hanlonr at cox.net> wrote:
> The attributes are documented, use ?? to see them:
>
> ??Numerator
>
> ??Denominator
>
>
> Bob Hanlon
>
> >
> > From: yehuda ben-shimol <bsyehuda at gmail.com>
To: mathgroup at smc.vnet.net
> > Date: 2005/07/17 Sun PM 01:03:15 EDT
> > Subject: [mg58780] [mg58770] Re: [mg58756] Eliminating Annoying Minus Signs
> >
> > Hi David,
> > Although not documented it seems that both Numerator and Denominator
> > are listable so
> > (-Numerator[#])/(-Denominator[#])&[test]
> > or
> > test//(-Numerator[#])/(-Denominator[#])&
> > will do the same without mapping.
> > yehuda
> >
> > On 7/17/05, David Park <djmp at earthlink.net> wrote:
> > > Yehuda,
> > >
> > > Thanks. That seems pretty good.
> > >
> > > We could turn this into a routine that could be mapped onto terms more
> > > generally in an expression.
> > >
> > > NDSignSwitch = (-Numerator[#])/(-Denominator[#]) &;
> > >
> > > test = {-((2*x)/(-1 + z)), -((2*y)/(-1 + z)), -1};
> > >
> > > NDSignSwitch /@ test
> > > {(2*x)/(1 - z), (2*y)/(1 - z), -1}
> > >
> > > David Park
> > > djmp at earthlink.net
> > > http://home.earthlink.net/~djmp/
> > >
> > >
> > >
> > > From: yehuda ben-shimol [mailto:bsyehuda at gmail.com]
To: mathgroup at smc.vnet.net
> > >
> > > Hi David,
> > > How about
> > > (- Numerator /@ test)/(- Denominator /@ test)
> > > this is not error prone.
> > > I'm almost certaint that there is more efficient way of doing this.
> > > I'll try to find it later
> > > regards
> > > yehuda
> > >
> > >
> >
> >
>
>