Tab the frequency of multiple variables with the same label

[Andre Silva]

I'm sorry if this has been asked a thousand times, but I haven't found the answer by searching the forums, or google.
I have 10 variables that use the same value label. I want to create a table like the ones you get with the tab varname command, where you get the number of observations in each variable according to the label values.
For example, I have the label 0 "no level" 1 "level 1" 2 "level 2". And I have the variables A1, A2 and A3. I need a table that looks lik this:

Label name	A1	A2	A3
no level	20	10	13
level 1	14	13	16
level 2	12	10	21

The values in the cells are the number of observations.
It seems simple enough, but how can I do this?

[Andrew Musau]

The following uses estpost and esttab from SSC by Ben Jann.

clear
*CREATE EXAMPLE DATA WITH LABELS
set obs 100
set seed 02072020
foreach name in A1 A2 A3{
    gen `name'= runiformint(0,2)
}
lab def mylab 0 "no level" 1 "level 1" 2 "level 2"

*START HERE
foreach name in A1 A2 A3{
lab values `name' mylab
local names `names' `name'
}
foreach name in A1 A2 A3{
   estpost tab `name'
   mat b = nullmat(b) \ e(b)
}
*TRANSPOSE MATRIX AND LABEL COLUMNS
mat b= b'
mat colnames b = `names'
*LIST USING ESTTAB
esttab matrix(b), nomtitle

Res.:

 esttab matrix(b), nomtitle

---------------------------------------------------
                       A1           A2           A3
---------------------------------------------------
no level               36           33           38
level 1                36           31           22
level 2                28           36           40
Total                 100          100          100
---------------------------------------------------

[Nick Cox]

tabm has been dedicated to this purpose since 1998. See the tab_chi package on SSC.

Demo:

ssc install tab_chi 
clear
set obs 100
set seed 2803

forval j = 1/3 {
     gen A`j' = floor(3 * runiform()^`j')
 }

tab1 A?

-> tabulation of A1  

         A1 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         36       36.00       36.00
          1 |         30       30.00       66.00
          2 |         34       34.00      100.00
------------+-----------------------------------
      Total |        100      100.00

-> tabulation of A2  

         A2 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         41       41.00       41.00
          1 |         37       37.00       78.00
          2 |         22       22.00      100.00
------------+-----------------------------------
      Total |        100      100.00

-> tabulation of A3  

         A3 |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |         66       66.00       66.00
          1 |         23       23.00       89.00
          2 |         11       11.00      100.00
------------+-----------------------------------
      Total |        100      100.00

tabm A?

           |              values
  variable |         0          1          2 |     Total
-----------+---------------------------------+----------
        A1 |        36         30         34 |       100 
        A2 |        41         37         22 |       100 
        A3 |        66         23         11 |       100 
-----------+---------------------------------+----------
     Total |       143         90         67 |       300 

tabm A?, transpose

           |             variable
    values |        A1         A2         A3 |     Total
-----------+---------------------------------+----------
         0 |        36         41         66 |       143 
         1 |        30         37         23 |        90 
         2 |        34         22         11 |        67 
-----------+---------------------------------+----------
     Total |       100        100        100 |       300

Naturally value labels will show up too if defined.

[Andre Silva]

tabm has been dedicated to this purpose since 1998. See the tab_chi package on SSC.

Demo:

ssc install tab_chi
clear
set obs 100
set seed 2803

forval j = 1/3 {
gen A`j' = floor(3 * runiform()^`j')
}

tab1 A?

-> tabulation of A1

A1 | Freq. Percent Cum.
------------+-----------------------------------
0 | 36 36.00 36.00
1 | 30 30.00 66.00
2 | 34 34.00 100.00
------------+-----------------------------------
Total | 100 100.00

-> tabulation of A2

A2 | Freq. Percent Cum.
------------+-----------------------------------
0 | 41 41.00 41.00
1 | 37 37.00 78.00
2 | 22 22.00 100.00
------------+-----------------------------------
Total | 100 100.00

-> tabulation of A3

A3 | Freq. Percent Cum.
------------+-----------------------------------
0 | 66 66.00 66.00
1 | 23 23.00 89.00
2 | 11 11.00 100.00
------------+-----------------------------------
Total | 100 100.00

tabm A?

| values
variable | 0 1 2 | Total
-----------+---------------------------------+----------
A1 | 36 30 34 | 100
A2 | 41 37 22 | 100
A3 | 66 23 11 | 100
-----------+---------------------------------+----------
Total | 143 90 67 | 300

tabm A?, transpose

| variable
values | A1 A2 A3 | Total
-----------+---------------------------------+----------
0 | 36 41 66 | 143
1 | 30 37 23 | 90
2 | 34 22 11 | 67
-----------+---------------------------------+----------
Total | 100 100 100 | 300

Naturally value labels will show up too if defined.

Thank you so much Nick! I didn't get to know the tabm command in class, that's going to be very useful.
And thank you to Andrew as well! Your solution was also pretty good!

Cheers!

[Mary Atieno]

tabm has been dedicated to this purpose since 1998. See the tab_chi package on SSC.

Demo:

ssc install tab_chi
clear
set obs 100
set seed 2803

forval j = 1/3 {
gen A`j' = floor(3 * runiform()^`j')
}

tab1 A?

-> tabulation of A1

A1 | Freq. Percent Cum.
------------+-----------------------------------
0 | 36 36.00 36.00
1 | 30 30.00 66.00
2 | 34 34.00 100.00
------------+-----------------------------------
Total | 100 100.00

-> tabulation of A2

A2 | Freq. Percent Cum.
------------+-----------------------------------
0 | 41 41.00 41.00
1 | 37 37.00 78.00
2 | 22 22.00 100.00
------------+-----------------------------------
Total | 100 100.00

-> tabulation of A3

A3 | Freq. Percent Cum.
------------+-----------------------------------
0 | 66 66.00 66.00
1 | 23 23.00 89.00
2 | 11 11.00 100.00
------------+-----------------------------------
Total | 100 100.00

tabm A?

| values
variable | 0 1 2 | Total
-----------+---------------------------------+----------
A1 | 36 30 34 | 100
A2 | 41 37 22 | 100
A3 | 66 23 11 | 100
-----------+---------------------------------+----------
Total | 143 90 67 | 300

tabm A?, transpose

| variable
values | A1 A2 A3 | Total
-----------+---------------------------------+----------
0 | 36 41 66 | 143
1 | 30 37 23 | 90
2 | 34 22 11 | 67
-----------+---------------------------------+----------
Total | 100 100 100 | 300

Naturally value labels will show up too if defined.

When tabulating these multiple variables, there a command that, in addition to the frequency, can include the percentages of the rows so that the outcome is similar to that of the "tab" command?

[Nick Cox]

#5 Surely, and one such command is called tabm

As its help documents, it supports

tabulate_options are options allowed with tabulate for two-way or one-way tables.

so that -- to continue the example of #3, quoted in entirety in #4 and #5 -- you can do things like his

. tabm A?, row

+----------------+
| Key            |
|----------------|
|   frequency    |
| row percentage |
+----------------+

           |              values
  variable |         0          1          2 |     Total
-----------+---------------------------------+----------
        A1 |        36         30         34 |       100
           |     36.00      30.00      34.00 |    100.00
-----------+---------------------------------+----------
        A2 |        41         37         22 |       100
           |     41.00      37.00      22.00 |    100.00
-----------+---------------------------------+----------
        A3 |        66         23         11 |       100
           |     66.00      23.00      11.00 |    100.00
-----------+---------------------------------+----------
     Total |       143         90         67 |       300
           |     47.67      30.00      22.33 |    100.00