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From | László Sándor <sandorl@gmail.com> |
To | statalist@hsphsun2.harvard.edu |
Subject | Re: st: -sts gen [newvar] = h- : why do I get monotonous (increasing) hazards? |
Date | Sun, 11 Jul 2010 16:15:49 +0200 |
Thanks, Steve. I thought this was what I was doing. -sts [graph]- shows a smoothed density of the deltaH over time. I guess delthaH *is* what I get from -sts gen-. So I must be plotting it the wrong way. Could you help me have a "step function" (in _t, I guessed) instead of -sts [graph], hazard- exactly as a histogram relates to a kernel density estimate? Thanks again, Laszlo On Sun, Jul 11, 2010 at 4:10 PM, Steve Samuels <sjsamuels@gmail.com> wrote: > > -sts gen- does not produce estimates of the hazard function. > > From the help: > > " h produces the estimated hazard component deltaH_j = H(t_j) - > H(t_(j-1)), where t_j is the current failure time and t_(j-1) is the > previous one. This is mainly a utility function used to calculate the > estimated cumulative hazard H(t_j), yet you can estimate the hazard > via a kernel smooth of the deltaH_j..." > > > Steve > > Steven Samuels > sjsamuels@gmail.com > 18 Cantine's Island > Saugerties NY 12477 > USA > Voice: 845-246-0774 > Fax: 206-202-4783 > > > 2010/7/11 László Sándor <sandorl@gmail.com>: > > Ahh, sorry, I forgot the code, though it is nothing surprising, I think: > > > > sts if clean == 1, hazard by(reviewerrole) tmax(60) /// > > title("Completion hazards by treatment group") /// > > xline(45) xline(28) xline(21, lc(green)) xline(38, lc(green)) > > graph export refhazard.pdf, replace > > > > cap drop hazard > > sts generate hazard = h, by(reviewerrole) > > > > 2010/7/11 László Sándor <sandorl@gmail.com>: > >> Hi, > >> > >> I wanted to use -sts gen- to produce my own variant of the hazard > >> graphs that -sts [graph]- produces. I am puzzled by what I get. That > >> graph shows (very plausibly for my data) varying hazard, sometimes > >> rising, sometimes falling, for all the four groups I plot it > >> separately (using the option -by-). When I used the -sts gen [newvar] > >> = h- command, I get hazards monotonously increasing in "time" (_t > >> after stset). > >> > >> What am I doing wrong? > >> > >> I paste you the commands I use, but they are not functional w/o my > >> data, I know. In any case, it would very useful if you could help me > >> reproduce the -sts graph ..., hazard- graphs using the output of -sts > >> gen ...=h-. (FYI, my goal is to use rough step function from -graph > >> bar- instead of smooth kernel density estimate.) > >> > >> Thank you! > >> > >> Laszlo > >> * > >> * 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/