Store tab command's results

[Nicolo Framarin]

Hi all!

How can I store in some locals the percentages shown by tab command?

Thank you in advance.

[William Lisowski]

The tab command does not return those values, so you will have to calculate the numbers some other way. How you do that depends on what your tab command was - one-way or two-way - and in the case of the latter, whether you wanted row percentages or column percentages.

Here's an example for a one-way tab.

. sysuse auto, clear
(1978 Automobile Data)

. tab foreign

   Car type |      Freq.     Percent        Cum.
------------+-----------------------------------
   Domestic |         52       70.27       70.27
    Foreign |         22       29.73      100.00
------------+-----------------------------------
      Total |         74      100.00

. preserve

. generate dummy = 1

. collapse (percent) dummy, by(foreign)

. list, clean

        foreign      dummy  
  1.   Domestic   70.27027  
  2.    Foreign   29.72973  

. local pctd = dummy[1]

. local pctf = dummy[2]

. restore

. display "domestic: `pctd' foreign: `pctf'"
domestic: 70.27027027027027 foreign: 29.72972972972973

.

[Nicolo Framarin]

Hi. Thank you!

While I was waiting, I wrote this code:

forvalues i = 1(1)10 {
quiet tab decile [aw=dwt], matcell(xxx)
quiet matlist xxx
local dec'i' = xxx['i', 1]
local dec'i' = dec'i' / obs
}

Do you think it is a proper alternative way to address the problem?

[William Lisowski]

. sysuse auto, clear
(1978 Automobile Data)

. tab foreign, matcell(table)

   Car type |      Freq.     Percent        Cum.
------------+-----------------------------------
   Domestic |         52       70.27       70.27
    Foreign |         22       29.73      100.00
------------+-----------------------------------
      Total |         74      100.00

. matrix list table

table[2,1]
    c1
r1  52
r2  22

. return list

scalars:
                  r(N) =  74
                  r(r) =  2

. local obs = r(N)

. local cat = r(r)

. forvalues i=1/`cat' {
  2.     local dec`i' = table[`i',1] / `obs'
  3. }

. display "domestic: `dec1' foreign: `dec2'"
domestic: .7027027027027027 foreign: .2972972972972973

.

[Nicolo Framarin]

Ok, thank you!