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From |
Nirina F <fstata@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: AW: why is this graph all over the place? |

Date |
Mon, 21 Sep 2009 16:44:15 -0400 |

No you are right, it is in [1,2]. I put it back to [1,2]. But I don't understand why I don't get the value of the marginal effects. all I get is: tab marg marg | Freq. Percent Cum. ------------+----------------------------------- 0 | 4,119 100.00 100.00 ------------+----------------------------------- Total | 4,119 100.00 On Mon, Sep 21, 2009 at 4:33 PM, Martin Weiss <martin.weiss1@gmx.de> wrote: > > <> > > > List the matrix and come back with the result... Is "varmain" really in > column 57? > > > > HTH > Martin > > > -----Ursprüngliche Nachricht----- > Von: owner-statalist@hsphsun2.harvard.edu > [mailto:owner-statalist@hsphsun2.harvard.edu] Im Auftrag von Nirina F > Gesendet: Montag, 21. September 2009 22:33 > An: statalist@hsphsun2.harvard.edu > Betreff: Re: st: AW: why is this graph all over the place? > > Oh, because When I did > mat list e(Xmfx_dydx) > I got: > e(Xmfx_dydx) [1, 57] > > > > On Mon, Sep 21, 2009 at 4:26 PM, Martin Weiss <martin.weiss1@gmx.de> wrote: >> >> <> >> >> " I corrected the matrix to >> replace marg=A[1,57] in `i'" >> >> Just give me a hint why you did that... >> >> You could simply pick one of the values of your varmain, and plug it into >> -mfx, such as seen here for the value you mentioned earlier. Then list the >> contents of the matrix with the marginal effects. >> >> >> ************* >> mfx, var(varmain) at(varmain=42.6) >> mat list e(Xmfx_dydx) >> ************* >> >> and show us the output... >> >> >> HTH >> Martin >> >> >> -----Ursprüngliche Nachricht----- >> Von: owner-statalist@hsphsun2.harvard.edu >> [mailto:owner-statalist@hsphsun2.harvard.edu] Im Auftrag von Nirina F >> Gesendet: Montag, 21. September 2009 22:14 >> An: statalist@hsphsun2.harvard.edu >> Betreff: Re: st: AW: why is this graph all over the place? >> >> Replacing it with -levelsof- made it work! Thanks. >> But I don't know why the marginal effects are not recorded. However, I >> corrected the matrix to >> replace marg=A[1,57] in `i' >> Thanks in advance again, >> Nirina >> On Mon, Sep 21, 2009 at 4:05 PM, Martin Weiss <martin.weiss1@gmx.de> > wrote: >>> >>> <> >>> >>> See, just when I thought I knew Stata: -levels- is not the abbreviation >> for >>> -levelsof-, it is an out-of-date command, apparently with limited >>> functionality. I never noticed, but you did with your non-integer > value... >>> So replace it by -levelsof- and it should work: >>> >>> >>> ************* >>> clear* >>> inp x >>> 1 >>> 3 >>> 4.5 >>> 4 >>> end >>> levelsof x >>> levels x >>> ************* >>> >>> >>> >>> HTH >>> Martin >>> >>> -----Ursprüngliche Nachricht----- >>> Von: owner-statalist@hsphsun2.harvard.edu >>> [mailto:owner-statalist@hsphsun2.harvard.edu] Im Auftrag von Nirina F >>> Gesendet: Montag, 21. September 2009 21:33 >>> An: statalist@hsphsun2.harvard.edu >>> Betreff: Re: st: AW: why is this graph all over the place? >>> >>> Thank you very much Martin. >>> I tried the example and it worked perfectly. When I tried with my >>> variables, the one that replaces mpg has one value that is not an >>> integer but is 42.6, therefore I got an error message: >>> levels varmain >>> varmain contains non-integer values >>> r(459); >>> I guess I should change the command -levels- with another one that >>> could list the values of varmain. >>> Also, I tried to recode varmain (42.6=43) but then I don't get >>> anything inside the new variable marg that keeps the marginal effects. >>> I am sure something is not right there because your example works >>> perfectly. I am going through each line to check. >>> >>> Nirina >>> >>> On Thu, Sep 17, 2009 at 6:19 PM, Martin Weiss <martin.weiss1@gmx.de> >> wrote: >>>> >>>> <> >>>> >>>> Try this and check it very carefully. I could not find such a picture in >>>> Long and Freese (2006), > http://www.stata-press.com/books/regmodcdvs.html, >>> - >>>> which I regard as a bad sign. >>>> >>>> Also note I am using the old -mfx- here, as I have not fully gotten my >>> head >>>> round the -margins- command. Hence the -version- statement... >>>> >>>> >>>> ************* >>>> vers 10.1 >>>> >>>> qui{ >>>> sysuse auto, clear >>>> prob for price mpg rep78 /* >>>> */ headroom trunk weight >>>> >>>> ins mpg >>>> loc uniq= r(N_unique) >>>> >>>> su mpg, mean >>>> prgen mpg, from(`r(min)') /* >>>> */ to(`r(max)') /* >>>> */ gen(prob) n(`uniq') >>>> >>>> >>>> levels mpg >>>> >>>> loc i 1 >>>> gen marg=0 >>>> >>>> foreach level in `r(levels)'{ >>>> mfx, var(mpg) at(mpg=`level') >>>> mat A = e(Xmfx_dydx) >>>> replace marg=A[1,2] in `i' >>>> loc ++i >>>> } >>>> >>>> } >>>> >>>> tw (connected probp1 probx), /* >>>> */ xti("Mpg") ytit("Probability") /* >>>> */ name(prob, replace) nodraw >>>> >>>> tw (connected marg probx), /* >>>> */ xti("Mpg") ytit("Marginal Effect") /* >>>> */ name(marginal, replace) nodraw >>>> >>>> >>>> gr combine prob marginal >>>> ************* >>>> >>>> >>>> >>>> HTH >>>> Martin >>>> >>>> >>>> -----Ursprüngliche Nachricht----- >>>> Von: owner-statalist@hsphsun2.harvard.edu >>>> [mailto:owner-statalist@hsphsun2.harvard.edu] Im Auftrag von Nirina F >>>> Gesendet: Donnerstag, 17. September 2009 18:46 >>>> An: statalist@hsphsun2.harvard.edu >>>> Betreff: Re: st: AW: why is this graph all over the place? >>>> >>>> Dear Martin, >>>> >>>> Thank you very much for the clarification. >>>> How about graphing the marginal effects next to that graph? >>>> nrina >>>> >>>> On Thu, Sep 17, 2009 at 12:04 PM, Martin Weiss <martin.weiss1@gmx.de> >>> wrote: >>>>> >>>>> <> >>>>> >>>>> The -prgen- command holds all other covariates at their mean by > default, >>>> so >>>>> my code has already taken care of your concern. To change the -title-s: >>>>> >>>>> ************* >>>>> sysuse auto, clear >>>>> prob for price mpg rep78 /* >>>>> */ headroom trunk weight >>>>> >>>>> ins mpg >>>>> loc uniq= r(N_unique) >>>>> >>>>> su mpg, mean >>>>> prgen mpg, from(`r(min)') /* >>>>> */ to(`r(max)') /* >>>>> */ gen(prob) n(`uniq') >>>>> >>>>> tw (connected probp1 probx), /* >>>>> */ xti("Mpg") ytit("Probability") >>>>> ************* >>>>> >>>>> >>>>> >>>>> HTH >>>>> Martin >>>>> >>>>> >>>>> -----Ursprüngliche Nachricht----- >>>>> Von: owner-statalist@hsphsun2.harvard.edu >>>>> [mailto:owner-statalist@hsphsun2.harvard.edu] Im Auftrag von Nirina F >>>>> Gesendet: Donnerstag, 17. September 2009 17:55 >>>>> An: statalist@hsphsun2.harvard.edu >>>>> Betreff: Re: st: AW: why is this graph all over the place? >>>>> >>>>> Thank you very much Martin for your help. It worked so well. >>>>> >>>>> I have a few questions: >>>>> >>>>> is it possible also to graph the marginal effects of just the mpg at >>>>> each value of mpg. I know if you calculate >>>>> . mfx >>>>> after >>>>> . prob for price mpg rep78 headroom trunk weight >>>>> >>>>> then you get the marg. effects at the mean value but I would like the >>>>> marginal effects at each value of mpg but keeping the other variables >>>>> at their mean. I am aware of the -at- option but it's just difficult >>>>> to graph it. >>>>> >>>>> Also, How would I change the name of the xaxis and yaxis of the > previous >>>>> graph? >>>>> >>>>> Thank you very much, >>>>> >>>>> Nrina >>>>> >>>>> >>>>> On Thu, Sep 17, 2009 at 8:00 AM, Martin Weiss <martin.weiss1@gmx.de> >>>> wrote: >>>>>> >>>>>> <> >>>>>> >>>>>> For these purposes, Scott Long`s -findit spost- comes in handy. Of >>>> course, >>>>>> Long and Freese (2006), >>> http://www.stata-press.com/books/regmodcdvs.html, >>>>> is >>>>>> the canonical reference for what you are trying to achieve. Try this: >>>>>> >>>>>> >>>>>> ************* >>>>>> sysuse auto, clear >>>>>> prob for price mpg rep78 /* >>>>>> */ headroom trunk weight >>>>>> >>>>>> ins mpg >>>>>> loc uniq= r(N_unique) >>>>>> >>>>>> su mpg, mean >>>>>> prgen mpg, from(`r(min)') /* >>>>>> */ to(`r(max)') /* >>>>>> */ gen(prob) n(`uniq') >>>>>> >>>>>> tw (connected probp1 probx) >>>>>> ************* >>>>>> >>>>>> >>>>>> >>>>>> HTH >>>>>> Martin >>>>>> >>>>>> >>>>>> -----Ursprüngliche Nachricht----- >>>>>> Von: owner-statalist@hsphsun2.harvard.edu >>>>>> [mailto:owner-statalist@hsphsun2.harvard.edu] Im Auftrag von Nirina F >>>>>> Gesendet: Donnerstag, 17. September 2009 13:41 >>>>>> An: statalist@hsphsun2.harvard.edu >>>>>> Betreff: st: why is this graph all over the place? >>>>>> >>>>>> Dear all, >>>>>> >>>>>> I would like to graph the predicted probabilities of having foreign >>>>>> against mpg in order to highlight the slope(basically the marginal >>>>>> effects) at each value of mpg. >>>>>> I run the following but it is all over the place because I think it is >>>>>> giving me the predicted probabilities from different variables. >>>>>> Could you help me in this please. also if you could help me graph the >>>>>> marginal effects of mpg from this probit equation against each value >>>>>> of mpg. >>>>>> >>>>>> probit foreign price mpg rep78 headroom trunk weight >>>>>> predict pmpg, p >>>>>> sort mpg >>>>>> twoway line pmpg mpg >>>>>> >>>>>> Thank you veyr much, >>>>>> N >>>>>> * >>>>>> * For searches and help try: >>>>>> * http://www.stata.com/help.cgi?search >>>>>> * http://www.stata.com/support/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/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/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/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/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/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/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/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/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/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/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/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/statalist/faq * http://www.ats.ucla.edu/stat/stata/

**Follow-Ups**:**AW: st: AW: why is this graph all over the place?***From:*"Martin Weiss" <martin.weiss1@gmx.de>

**References**:**st: why is this graph all over the place?***From:*Nirina F <fstata@gmail.com>

**Re: st: AW: why is this graph all over the place?***From:*Nirina F <fstata@gmail.com>

**Re: st: AW: why is this graph all over the place?***From:*Nirina F <fstata@gmail.com>

**Re: st: AW: why is this graph all over the place?***From:*Nirina F <fstata@gmail.com>

**Re: st: AW: why is this graph all over the place?***From:*Nirina F <fstata@gmail.com>

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