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st: Re:using replace command and retrieving conf. intervals


From   kusi@yorku.ca
To   statalist@hsphsun2.harvard.edu
Subject   st: Re:using replace command and retrieving conf. intervals
Date   Tue, 23 Jul 2002 15:29:57 -0400

while trying to figure out how the  confidence interval at 95% level is linked 
to the standard error, I came up with following problem (as I tried to use the 
replace command) : the parts of the command that connect are just for standard 
errors 0, .25, .5 and .75 .Obviously the standard errors visible on the screen 
are not perfectly consistent with what is visible plus the hidden parts 
(lingering parts) .Can anyone help me with that.And while I am at it ,can 
anyone tell me how to retrieve the lower boundaries  and the upper boundaries 
of confidence intervals  ?

    
.        capture program drop lnsimvz1

. 
.         program define lnsimvz1
  1.                 if "`1'"=="?" {
  2.                         global S_1 " pu pl p se t mean"
  3.                         exit
  4.                 }
  5.                 drop _all
  6.                 use clt
  7.                 sample 4
  8.                ttest a = 3
  9.               return list
 10.           post `1'  r(p_u) r(p_l) r(p) r(se) r(t) r(mu_1) 
 11.         end

. 
. 
end of do-file

. simul  lnsimvz1 , reps(1000)

. list in 1/5

            pu         pl          p         se          t       mean 
  1.   .681191    .318809   .6376181   .4787135  -.5222329       2.75  
  2.  .7524873   .2475127   .4950253   .6454972  -.7745967        2.5  
  3.         .          .          .          0          .          4  
  4.  .7524873   .2475127   .4950253   .6454972  -.7745967        2.5  
  5.        .5         .5          1   .7071068          0          3  

. tab se

         se |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         34        3.40        3.40
        .25 |        134       13.40       16.80
   .2886751 |        108       10.80       27.60
   .4082483 |        117       11.70       39.30
   .4787135 |        232       23.20       62.50
         .5 |         67        6.70       69.20
   .5773503 |         52        5.20       74.40
   .6291529 |         62        6.20       80.60
   .6454972 |         49        4.90       85.50
   .7071068 |         57        5.70       91.20
        .75 |         80        8.00       99.20
   .8660254 |          8        0.80      100.00
------------+-----------------------------------
      Total |       1000      100.00

. do "C:\WINDOWS\TEMP\STD010000.tmp"

. gen interval = 1.837386 

. replace interval  = 0 if se == 0
(34 real changes made)

. replace interval = 1.591224 if se == .25
(134 real changes made)

. replace interval = 1.591224  if se == .2886751
(0 real changes made)

. replace interval = 2.598456 if se == .4082483
(0 real changes made)

. replace interval = 3.04696 if se == .4787135
(0 real changes made)

. replace interval =3.182446 if se == .5
(67 real changes made)

. replace interval = 3.674772  if se == .5773503
(0 real changes made)

. replace interval = 4.0044902 if se == .6291529
(0 real changes made)

. replace interval = 4.1085203 if se == .6454972
(0 real changes made)

. replace interval =4.5006584 if se == .7071068
(0 real changes made)

. replace interval = 4.7736697 if se == .75
(80 real changes made)

. replace interval = 5.5121583 if se == .8660254
(0 real changes made)

. 
. 
end of do-file

. 
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