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| From | Nick Cox <njcoxstata@gmail.com> |
| To | "statalist@hsphsun2.harvard.edu" <statalist@hsphsun2.harvard.edu> |
| 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 njcoxstata@gmail.com On 29 April 2013 12:30, Kasal Roman <kasalroman@gmail.com> 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 <njcoxstata@gmail.com> wrote: >> I see no evidence here for that extraordinary claim. >> >> Sorry, I am still lost on what you want. >> Nick >> njcoxstata@gmail.com >> >> >> On 29 April 2013 12:17, Kasal Roman <kasalroman@gmail.com> 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 <njcoxstata@gmail.com> 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 >>>> njcoxstata@gmail.com >>>> >>>> >>>> On 29 April 2013 11:23, Kasal Roman <kasalroman@gmail.com> 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. >>>> * >>>> * For searches and help try: >>>> * http://www.stata.com/help.cgi?search >>>> * http://www.stata.com/support/faqs/resources/statalist-faq/ >>>> * http://www.ats.ucla.edu/stat/stata/ >>> * >>> * For searches and help try: >>> * http://www.stata.com/help.cgi?search >>> * http://www.stata.com/support/faqs/resources/statalist-faq/ >>> * http://www.ats.ucla.edu/stat/stata/ >> * >> * For searches and help try: >> * http://www.stata.com/help.cgi?search >> * http://www.stata.com/support/faqs/resources/statalist-faq/ >> * http://www.ats.ucla.edu/stat/stata/ > * > * For searches and help try: > * http://www.stata.com/help.cgi?search > * http://www.stata.com/support/faqs/resources/statalist-faq/ > * http://www.ats.ucla.edu/stat/stata/ * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/