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Re: st: Double loop over unbalanced panel
From
WEBER Sylvain <[email protected]>
To
"<[email protected]>" <[email protected]>
Subject
Re: st: Double loop over unbalanced panel
Date
Sat, 3 Nov 2012 05:53:52 +0000
Hi.
I think you don't need any loop. - by - can be used instead.
Try
bysort id (t): replace chc=(chc[_n-1]*ph+cont)/p if mi(chc)
Note that the - if mi(chc) - condition is very important. Otherwise, you would replace all values of chc; not only missing values.
Best,
Sylvain
Le 2 nov. 2012 à 14:00, "Fernando Luco" <[email protected]> a écrit :
> Hi Nick,
>
> The data and the formula look as follows
>
> input id t str1 ch p str1 chh ph cont con_c chc
> 1 1 "a" 2 "" . 1 0.5 1 1
> 1 2 "b" 3 "a" 4 3 1 .
> 1 2 "b" 3 "a" 4 3 1 .
> 1 3 "a" 1 "b" 2 2 2 .
> 1 4 "c" 4 "a" 3 3 .75 .
> 1 5 "d" 2 "c" 5 1 .5 .
> 2 3 "d" 2 "" . 1 1 2
> 2 4 "a" 3 "d" 3 3 1 .
> 2 5 "b" 1 "a" 2 2 2 .
> 2 6 "a" 2 "b" 2 1 .5 .
> end
>
> foreach k of numlist 1/2{
> foreach w of numlist 2/T_k{
> replace chc=(chc[`w'-1]*ph+cont)/p if _n==`w' & id==`k'
> }
> }
>
> Thanks,
>
> Fernando
>
> On Fri, Nov 2, 2012 at 3:39 PM, Nick Cox <[email protected]> wrote:
>> I think the best advice depends on what -formula()- is, which you
>> don't tell us.
>>
>> That said
>>
>> foreach of numlist ...
>>
>> in both your examples can be recast more simply as -forval- loops.
>>
>> Nick
>>
>> On Fri, Nov 2, 2012 at 8:12 PM, Fernando Luco <[email protected]> wrote:
>>> Hi,
>>>
>>> I have an unbalanced panel and I need to do a loop over individuals and
>>> observations. My data looks as follows (I have other variables that are not
>>> represented in this example)
>>>
>>> id t chc
>>> 1 1 .5
>>> 1 2 .
>>> 1 3 .
>>> 1 4 .
>>> 1 5 .
>>> 2 3 1
>>> 2 4 .
>>> 2 5 .
>>> 2 6 .
>>>
>>> What I want to do is, for each individual (id) to complete the values in
>>> chc according to a formula that depends on other variables. However, the
>>> number of times that each individual appears differs across individuals. I
>>> would like to do something such as
>>>
>>> foreach k of numlist 1/2 { /*the 2 has to be changed to the total number of
>>> individuals*/
>>> foreach w of numlist 2/T_k { /* where T_k corresponds to the number of
>>> times individual 2 appears*/
>>> replace chc=formula(`w')
>>> }
>>> }
>>>
>>> I don't know how to define T_k in the correct way such that it varies
>>> across individuals (so 5 for individual 1 and 4 for individual 2).
>>>
>>> Thanks,
>>>
>>> Fernando
>>> *
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>> *
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> *
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