Using foreach in loop

[Sirak Bahta]

Dear All,
I have posted a question with regard to looping, but I confess my question is vegue.
Let me try with a simple one.
I have a data that looks like this:

Region	crop	production	value sold	quantity sold	Price
1	1	30	34.2	20	1.71
1	1	44	0	0	.
1	1	25	0	0	.
1	1	63	98.05	53	1.85
2	1	96	206.4	86	2.4
2	1	25	30	15	2
2	1	14	0	0	.
2	1	12	0	0	.
3	1	13	5.7	3	1.9
3	1	65	0	0	.
3	1	14	5.8	4	1.45
3	1	54	70.4	44	1.6
4	1	58	0	0	.
4	1	74	36	30	1.2
4	1	62	0	0	.
4	1	35	32.5	25	1.3

Now I want to replace the missing value of variable price based on regional average
I did the following:
Keep if crop ==1
gen work = .
sort r1_region
foreach v of var cr_priceperKG {
by r1_region: replace work = sum(`v') / sum(`v' < .)
by r1_region: replace work = work[_N]
replace `v' = work if `v'==.
drop work
}
}
This replaced the missing values of price based on regional average.
I want to extend this to include many types of crops at once instead of keeping crop number x and drop others.
Thanks for the help
Sirak

[Sean Lambert]

This isn't really a mata question, as all of your code is just regular stata.

I'm a little confused as to why you are replacing the missing values at all.

If quantity sold == 0 then price should be missing.

[Steve Samuels]

Yes, repost in the General forum, or most of the people who might help you will never see this.