Hello to everyone!

I am very new to Stata and I am struggling with a problem, which I cannot solve so far. I have three dummy variables: group 1, group 2 and group 3
I am trying to find a way to sum the frequencies of all groups if they take the value 0 or 1.

For example I want to get totalzero=3.800 + 1.366 + 1.500 and totalone = 261 + 2.008 + 2.561


. tab1 group1 group2 group3

-> tabulation of group1

group1 | Freq. Percent Cum.
----------------------------------------------
0 | 3,800 93.57 93.57
1 | 261 6.43 100.00
-----------------------------------------------
Total | 4,061 100.00

-> tabulation of group2

group2 | Freq. Percent Cum.
-----------------------------------------------
0 | 1,366 40.49 40.49
1 | 2,008 59.51 100.00
-----------------------------------------------
Total | 3,374 100.00

-> tabulation of group3

group3 | Freq. Percent Cum.
-----------------------------------------------
0 | 1,500 36.94 36.94
1 | 2,561 63.06 100.00
-----------------------------------------------
Total | 4,061 100.00

Could you please explain to me what can I do? I tried to add the 3 dummy variables first but it doesnt give me the sum of frequencies.


Thank you very much in advance!!!