making loop with the values within the variable

[Young Hwang]

Hello,

I have one of the variables G1 which has values from 1 to 17.
Then I want to make a loop as below,but it didn't work out.
Anyone can help what is the problem? thanks in advance.

foreach i in G1 {
sum sw20h if G1==`i'
global Ng`i'=r(sum)
}

[Rich Goldstein]

help levelsof

and look at the examples one of shows how to use -levelsof- with -foreach-

[Young Hwang]

I tried with this code, but still doesn't work.

levelsof G1, local(G1)
foreach i of local G1 {
sum sw20h if G1==`i'
global Ng`i'=r(sum)
}

Where is wrong?

[Nick Cox]

tabstat sw20h, s(sum) by(G1)

is more direct as a way of showing sums.

As for what is wrong, what does "doesn't work" mean?

https://www.statalist.org/forums/help#stata advises:

Never say just that something "doesn't work" or "didn't work", but explain precisely in what sense you didn't get what you wanted.

[Nick Cox]

It seems from your other thread that you want to do further calculations with these totals. You don't give any data example but the following silly example -- which all Stata users can run -- may help -- and help to show that loops are often not needed.

. sysuse auto, clear
(1978 Automobile Data)

. egen total_price = total(price), by(rep78)

. tabdisp rep78, c(total_price)

-----------------------
Repair    |
Record    |
1978      | total_price
----------+------------
        1 |        9129
        2 |       47741
        3 |      192877
        4 |      109287
        5 |       65043
        . |       32152
-----------------------

* same results! 
. tabstat price, by(rep78) s(sum) missing

Summary for variables: price
     by categories of: rep78 (Repair Record 1978)

   rep78 |       sum
---------+----------
       1 |      9129
       2 |     47741
       3 |    192877
       4 |    109287
       5 |     65043
       . |     32152
---------+----------
   Total |    456229
--------------------

. su price, meanonly

. di r(sum)
456229

. gen fraction_total = total_price / r(sum)

. tabdisp rep78, c(total_price fraction_total)

------------------------------------------
Repair    |
Record    |
1978      |    total_price  fraction_total
----------+-------------------------------
        1 |           9129        .0200097
        2 |          47741        .1046426
        3 |         192877        .4227636
        4 |         109287        .2395442
        5 |          65043        .1425666
        . |          32152        .0704734
------------------------------------------

. format fraction_total %04.3f

. tabdisp rep78, c(total_price fraction_total)

------------------------------------------
Repair    |
Record    |
1978      |    total_price  fraction_total
----------+-------------------------------
        1 |           9129           0.020
        2 |          47741           0.105
        3 |         192877           0.423
        4 |         109287           0.240
        5 |          65043           0.143
        . |          32152           0.070
------------------------------------------