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| From | Nick Cox <njcoxstata@gmail.com> |
| To | "statalist@hsphsun2.harvard.edu" <statalist@hsphsun2.harvard.edu> |
| Subject | Re: st: graph results of bitest stratified with by(var) |
| Date | Thu, 23 Jan 2014 18:22:23 +0000 |
I see, but you can just calculate that from the -statsby- results. Nick njcoxstata@gmail.com On 23 January 2014 18:19, Richard Goldstein <richgold@ix.netcom.com> wrote: > 1. Michael, if you look at -h levelsof- there is an example showing its > use with -foreach- > > 2. Nick, I did not suggest -statsby- because Michael asked for something > that is not in the return list (r(k)/r(N)) and I don't think that this > is allowed with -statsby-, but maybe I'm wrong about that? > > Rich > > On 1/23/14, 1:07 PM, Nick Cox wrote: >> -search foreach- does exactly what you ask, namely point to sources on >> -foreach-. >> >> But -help statsby- does even better. >> >> Here's a dopey example. >> >> sysuse auto, clear >> statsby N=r(N) k=r(k) p_l=r(p_l) p_u=r(p_u) , by(rep78): bitest >> foreign=.2 >> list >> >> Nick >> njcoxstata@gmail.com >> >> On 23 January 2014 17:55, Michael McCulloch <mm@pinestreetfoundation.org> >> >>> Thank you Richard, that's exactly what I'm wanting to achieve. >>> I understand now that -bysort- clears the scalars at each re-call. >>> >>> Can you point me to primers so I can learn how to wrap this into a -foreach- / -levelsof- loop? >> >> >> On Jan 23, 2014, at 5:45 AM, Richard Goldstein wrote: >>> >>>> If I understand what you want correctly, you cannot do it with bysort >>>> because each time you do the test the set of returned values (the >>>> "r()"'s) will be replaced and the old ones lost >>>> >>>> you can do this within a -foreach- loop (you may need -levelsof- first) >>>> in which you quietly do the -bitest- and then list your results for that >>>> test and then do the next -bitest-, etc. >>>> >>>> here is an example of how to use the returned values: >>>> >>>> . sysuse auto >>>> >>>> . bitest foreign=.2 >>>> >>>> Variable | N Observed k Expected k Assumed p Observed p >>>> -------------+------------------------------------------------------------ >>>> foreign | 74 22 14.8 0.20000 0.29730 >>>> >>>> Pr(k >= 22) = 0.029904 (one-sided test) >>>> Pr(k <= 22) = 0.984075 (one-sided test) >>>> Pr(k <= 7 or k >= 22) = 0.041800 (two-sided test) >>>> r; t=0.09 8:39:38 >>>> >>>> . di r(N) _skip(2) r(P_p) _skip(2) r(k)/r(N) _skip(2) r(p) >>>> 74 .2 .2972973 .04179963 >>>> >>>> I have not put headers on the columns and have not done several other >>>> things you might want (e.g., print format for results) but this should >>>> give the basic idea, assuming I have correctly understood you >> >> On 1/23/14, 12:57 AM, Michael McCulloch wrote: >> >>>>> I am using bitest for a two-sided test on whether the mean of varB is different than 0.2, and testing on each level of varA: >>>>> bysort varA: bitest varB=.2 >>>>> >>>>> varA has ~30 values. I wish to display these in a table (showing N, observed p, >>>> expected p, and the two-sided p-value), without manual cut-and-paste, as >>>> the test >>>> will be used to monitor an ongoing training program. >>>>> >>>>> I note that the results of bitest are stored as: >>>>> r(N) number N of trials >>>>> r(P_p) assumed probability p of success >>>>> r(k) observed number k of successes >>>>> r(p_l) lower one-sided p-value >>>>> r(p_u) upper one-sided p-value >>>>> r(p) two-sided p-value >>>>> >>>>> However, I do not know how one uses these r(**) values. Can anyone suggest how one >>>> would go about this? > * > * 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/