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       log:  C:\mydocs\MPH\Text\SecondEdition\WebDoFiles\2.16.Poison.log
  log type:  text
 opened on:  26 Dec 2007, 20:27:58

. *  2.16.Poison.log
. *
. *  Perform a residual analysis of the linear regression of plasma glycolate
. *  against arterial pH from the poison data set (Brent et al. 1999).
. *
. use C:\WDDtext\2.12.Poison.dta, clear

. regress glyco ph

      Source |       SS       df       MS              Number of obs =      18
-------------+------------------------------           F(  1,    16) =   61.70
       Model |  87664.6947     1  87664.6947           Prob > F      =  0.0000
    Residual |  22731.9877    16  1420.74923           R-squared     =  0.7941
-------------+------------------------------           Adj R-squared =  0.7812
       Total |  110396.682    17   6493.9225           Root MSE      =  37.693

------------------------------------------------------------------------------
       glyco |      Coef.   Std. Err.      t    P>|t|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
          ph |  -414.9666   52.82744    -7.86   0.000    -526.9558   -302.9775
       _cons |    3082.58   381.0188     8.09   0.000     2274.856    3890.304
------------------------------------------------------------------------------

. predict residual, rstudent

. display _N
18

. display invttail(_N-3,.025)
2.1314495

. scatter residual ph || lowess residual ph, bwidth(.99)                  ///
>     , yscale(range(-2.13 2.13))  xlabel(6.9 (.1)7.5)                    ///
>       yline(-2.13 2.13, lcolor(gray) lpattern(dash))                    ///
>       yline(0, lcolor(gray)) legend(off)

. log close
       log:  C:\mydocs\MPH\Text\SecondEdition\WebDoFiles\2.16.Poison.log
  log type:  text
 closed on:  26 Dec 2007, 20:28:01
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