Re: Why won't Horner[] work?
- To: mathgroup at smc.vnet.net
- Subject: [mg59015] Re: Why won't Horner[] work?
- From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
- Date: Wed, 27 Jul 2005 01:24:37 -0400 (EDT)
- Organization: The Open University, Milton Keynes, U.K.
- References: <dc4r39$i9$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Paul McHale wrote:
> When I issue the command:
>
> In:= Fit[ {{1,200},{200,0},{400,200}}, {1,x,x^2}, x]
>
> Out:= 202.01 - 2.01508 x + 0.00502513 x^2
>
> This seems good. But when I do
>
>
> In:= Horner[Fit[ {{1,200},{200,0},{400,200}}, {1,x,x^2}, x]]
>
> Out:= Horner[202.01 - 2.01508 x + 0.00502513 x^2]
>
>
> Why doesn't it evaluate the polynomial? To I need to convert the
> output of fit?
>
> Thanks,
> Paul
>
Hi Paul,
You must load the package *Algebra`Horner* before you can use the
instruction *Horner[]*.
In[1]:=
Needs["Algebra`Horner`"]
In[2]:=
Horner[Fit[{{1, 200}, {200, 0}, {400, 200}},
{1, x, x^2}, x]]
Out[2]=
202.0100502512563 + (-2.0150753768844227 +
0.005025125628140706*x)*x
Best regards,
/J.M.