Count the number of a specific value in differnet variables

[Radhouene DOGGUI]

Dear Honourable members of the forum,

Probably my question is too easy for you, but I got stuck for the following task.
My data configguration is like that

Year	id	Var1	var 2	var3	New var
2005	20051	1	0	0	1
2005	20052	0	0	0	0
2005	20053	0	1	1	2
2005	20054	1	1	1
2005	20055	1	1	1
2005	20056	1	1	1
2005	20057	0	1	1
2005	20058	0	0	0
2005	20059	1	0	1

I would like to create a new variable that count of a specific value "=1" observed in the different variables from var 1 to var 3 for each subject. For example here, the subject with id 20053, have a score=2 for the new var because the number 1 was observed 2 times within the three studied variables (var1 to var 3).
Thank you for your help.

[Wouter Wakker]

See help egen, specifically the rowtotal() function.

[John Ash]

If var1/2/3 can only take the values 0/1. then use:

gen NewVar = Var1 + Var2 + Var3

[Radhouene DOGGUI]

Thank you wouter and John

please another question. if one of the column contains number with decimals what I should do?

Year	id	Var1	var 2	var3	New var
2005	20051	1	0.5	0.4	1
2005	20052	0	0	0	0
2005	20053	0	1	0.6	1
2005	20054	1	1	1
2005	20055	1	1	0.5
2005	20056	1	1	1
2005	20057	0	1	1
2005	20058	0	0	0
2005	20059	1	0	1

[Nick Cox]

Compare #2. Perhaps you seek the rowmax() function of egen.

[Wouter Wakker]

gen new_var = .
foreach var of varlist var1 var2 var3 {
   replace new_var = new_var + `var' if `var' == 1
}

[Radhouene DOGGUI]

Compare #2. Perhaps you seek the rowmax() function of egen.

Thank you Nick. But this function give me the highest value however, I would like that the new var contains the number of occurence of "1" in each variables

[Radhouene DOGGUI]

gen new_var = .
foreach var of varlist var1 var2 var3 {
replace new_var = new_var + `var' if `var' == 1
}

Thank you Wouter but it doesn't work

[Rich Goldstein]

first, please read the FAQ and follow its advice, esp re: use of -dataex-

second, I think you want the "anycount" function of -egen- with val(1); if you use -dataex- it is easy to test, and thus provide, exact code

[Sergiy Radyakin]

Wouter Wakker 's code above would have been the answer as well, but it must initiate the new variable new_var with 0 (zero) not with a . (missing).

+1 for the anycount() function, which should be sufficient in this case.

[Radhouene DOGGUI]

Thanks Rich
Thanks Sergiy, Yes anycount worked perfectly.