Re: st: graph results of bitest stratified with by(var)

[Richard Goldstein <richgold@ix.netcom.com>]

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

Rich

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?
> 
> Best wishes,
> Michael McCulloch
> 
> --
> Pine Street Foundation, since 1989
> 124 Pine Street | San Anselmo | California | 94960-2674  
> P: (415) 407-1357 | F: (206) 338-2391 | http://www.PineStreetFoundation.org
*
*   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/