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Re: st: theory reg vs. qreg
From
Nick Cox <[email protected]>
To
"[email protected]" <[email protected]>
Subject
Re: st: theory reg vs. qreg
Date
Mon, 29 Apr 2013 12:38:30 +0100
Sorry, nothing here is clear to me.
If you have a point of principle, you need to define your terms.
If you have results from Stata that puzzle you, you can give us an
example, preferably using a dataset we can all access.
Nick
[email protected]
On 29 April 2013 12:30, Kasal Roman <[email protected]> wrote:
> but do you agree with:
>
> if "reg" gives me the general results:
> A) Y1=b1
> B) Y2=a2*x+b2
>
> on the same data
> then must be:
>
> Y2=mean(x)*x+b2=b1=Y1 ?
>
> Is the assumption clear now?
>
> thx
>
> On Mon, Apr 29, 2013 at 1:21 PM, Nick Cox <[email protected]> wrote:
>> I see no evidence here for that extraordinary claim.
>>
>> Sorry, I am still lost on what you want.
>> Nick
>> [email protected]
>>
>>
>> On 29 April 2013 12:17, Kasal Roman <[email protected]> wrote:
>>> of course I don't mean this, I know a2!=mean(x) but IF you put
>>> a2=mean(x) you get the first method result with the "reg" command :)
>>>
>>> On Mon, Apr 29, 2013 at 12:39 PM, Nick Cox <[email protected]> wrote:
>>>>
>>>> What you want is not at all clear. In fact, you seem confused about some basics.
>>>>
>>>> For example, if you fit a regression
>>>>
>>>> Y2=a2*x+b2
>>>>
>>>> it's not true that a2 = mean(x).
>>>>
>>>> What do you mean by "deactivate" a coefficient?
>>>>
>>>> -qreg y-
>>>>
>>>> works; it's just a round-about way of calculating the median of -y-,
>>>> which you can do directly with -summarize-.
>>>>
>>>> Nick
>>>> [email protected]
>>>>
>>>>
>>>> On 29 April 2013 11:23, Kasal Roman <[email protected]> wrote:
>>>> > Please,
>>>> >
>>>> >
>>>> > the "reg" command gives me these results:
>>>> >
>>>> > A) Y1=b1
>>>> >
>>>> > B) Y2=a2*x+b2
>>>> >
>>>> > then
>>>> >
>>>> > Y2=mean(x)*x+b2=b1=Y1
>>>> >
>>>> >
>>>> > How is it with "qreg"? How could I deactivate the "a2" coefficient
>>>> > without a need to estimate two functions with the "qreg" command? How
>>>> > to get the result of "b1" just with the B) method through the "qreg"
>>>> > command? I know neither mean(x) nor median(x) fit.
>>>> *
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>>> *
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>> *
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> *
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