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Re: linfit and regress questions [message #56690 is a reply to message #56686]

Sun, 11 November 2007 08:49

Vince Hradil
Messages: 574
Registered: December 1999

Senior Member

On Nov 11, 10:42 am, rlaybe...@hotmail.com wrote:
> On 11 Nov, 16:37, hradilv <hrad...@yahoo.com> wrote:
>
>
>
>> On Nov 11, 10:27 am, rlaybe...@hotmail.com wrote:
>
>>> Hi
>
>>> I am interested in fitting a line of the form y=mx+c using regress or
>>> linfit. I want the option of fixing the value of c at zero. Can I do
>>> this in either of these 2 functions or would I need to use something
>>> else?
>
>>> Thanks
>
>>> Russ
>
>> Just write it yourself:
>
>> mhat = total(x*y)/total(x*x)
>
>> http://mallit.fr.umn.edu/fr5218/reg_refresh/origin.html
>
> thanks. is that really true? this gives the best fit? great, that's
> one problem solved. what about if I want to set the intercept to c1?
>
> russ

Transform the data?

mhat = total(x*(y-c1))/total(x*x)

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[Message index]

		Re: linfit and regress questions By: rlayberry on Mon, 12 November 2007 02:02
		Re: linfit and regress questions By: Vince Hradil on Sun, 11 November 2007 08:49
		Re: linfit and regress questions By: rlayberry on Sun, 11 November 2007 08:42
		Re: linfit and regress questions By: Vince Hradil on Sun, 11 November 2007 08:37
		Re: linfit and regress questions By: Craig Markwardt on Mon, 12 November 2007 19:16

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