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. version 9.0

. clear

. use microdat

. help (table)

. chelp (table)

. search (chi2)
[...]

. codebook

[...]

. help (count)

. count if age>25
    5

. describe fum

              storage  display     value
variable name   type   format      label      variable label
-------------------------------------------------------------------------------
fum             byte   %8.0g                  

. drop if age>40
(1 observation deleted)

. generate eversmk=1 if  fum>0
(2 missing values generated)

. help (replace)

. replace eversmk =0 if eversmk==.
(2 real changes made)

. help (label)

. label define smk 0 never 1 current 2 former

. label values  fum smk

. list fum

     +---------+
     |     fum |
     |---------|
  1. | current |
  2. |  former |
  3. | current |
  4. |   never |
  5. |   never |
     +---------+

. rename fum smoking

. list smok

     +---------+
     | smoking |
     |---------|
  1. | current |
  2. |  former |
  3. | current |
  4. |   never |
  5. |   never |
     +---------+

. sort age

. l age

     +-----+
     | age |
     |-----|
  1. |  23 |
  2. |  27 |
  3. |  29 |
  4. |  33 |
  5. |  36 |
     +-----+

. help (save)

. save microdat2
file microdat2.dta saved

. exit, clear