-------------------------------------------------------------------------------
      name:  <unnamed>
       log:  /disk/oldadmin/homes/web/html/stata/efficient/levelsof.log
  log type:  text
 opened on:  28 Oct 2019, 16:46:37

. set obs 100000000
number of observations (_N) was 0, now 100,000,000

. set rmsg on
r; t=0.00 16:46:38

. gen r=runiform()
r; t=2.28 16:46:40

. gen recno=_n
r; t=1.40 16:46:41

. sort r
r; t=86.84 16:48:08

. gen v=mod(recno,100000)
r; t=1.82 16:48:10

. summarize

    Variable |        Obs        Mean    Std. Dev.       Min        Max
-------------+---------------------------------------------------------
           r |100,000,000    .5000029    .2886991   5.55e-09          1
       recno |100,000,000    5.00e+07    2.89e+07          1   1.00e+08
           v |100,000,000    49997.34    28867.51          0      99999
r; t=1.95 16:48:12

. quietly levelsof v,local(wlevels)
r; t=21.97 16:48:34

. 
. gen x=mod(recno,100)
r; t=1.96 16:48:36

. summarize

    Variable |        Obs        Mean    Std. Dev.       Min        Max
-------------+---------------------------------------------------------
           r |100,000,000    .5000029    .2886991   5.55e-09          1
       recno |100,000,000    5.00e+07    2.89e+07          1   1.00e+08
           v |100,000,000    49997.34    28867.51          0      99999
           x |100,000,000    48.33554    28.85554          0         99
r; t=2.60 16:48:38

. quietly levelsof x,local(xlevels)
r; t=17.16 16:48:56

. 
. gen y=mod(recno,10)
r; t=2.03 16:48:58

. summarize

    Variable |        Obs        Mean    Std. Dev.       Min        Max
-------------+---------------------------------------------------------
           r |100,000,000    .5000029    .2886991   5.55e-09          1
       recno |100,000,000    5.00e+07    2.89e+07          1   1.00e+08
           v |100,000,000    49997.34    28867.51          0      99999
           x |100,000,000    48.33554    28.85554          0         99
           y |100,000,000    4.083886     2.84198          0          9
r; t=3.27 16:49:01

. quietly levelsof y,local(ylevels)
r; t=7.67 16:49:09

. 
. drop v x y 
r; t=0.00 16:49:09

. 
. gen v=string(mod(recno,1000))
r; t=52.72 16:50:01

. summarize

    Variable |        Obs        Mean    Std. Dev.       Min        Max
-------------+---------------------------------------------------------
           r |100,000,000    .5000029    .2886991   5.55e-09          1
       recno |100,000,000    5.00e+07    2.89e+07          1   1.00e+08
           v |          0
r; t=1.41 16:50:03

. quietly levelsof v,local(vlevels)
r; t=653.53 17:00:56

. 
. gen x=string(mod(recno,100))
r; t=49.98 17:01:46

. summarize

    Variable |        Obs        Mean    Std. Dev.       Min        Max
-------------+---------------------------------------------------------
           r |100,000,000    .5000029    .2886991   5.55e-09          1
       recno |100,000,000    5.00e+07    2.89e+07          1   1.00e+08
           v |          0
           x |          0
r; t=1.50 17:01:48

. quietly levelsof x,local(xlevels)
r; t=558.78 17:11:07

. 
. gen y=string(mod(recno,10))
r; t=36.70 17:11:43

. summarize

    Variable |        Obs        Mean    Std. Dev.       Min        Max
-------------+---------------------------------------------------------
           r |100,000,000    .5000029    .2886991   5.55e-09          1
       recno |100,000,000    5.00e+07    2.89e+07          1   1.00e+08
           v |          0
           x |          0
           y |          0
r; t=1.59 17:11:45

. quietly levelsof y,local(ylevels)
r; t=501.93 17:20:07

. 
. quietly table y
r; t=85.63 17:21:33

. collapse (sum) r,by(x)
r; t=85.10 17:22:58

. 
. 
end of do-file

r; t=0.00 17:22:58
. exit,clear