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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 15:33:22 -0400 |

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/

**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>

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