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Re: st: Accumulated mean and standard deviation
From
Pedro Nakashima <[email protected]>
To
[email protected]
Subject
Re: st: Accumulated mean and standard deviation
Date
Sun, 8 Jan 2012 20:34:08 -0200
Thank you Matthew, It worked perfectly!
Best,
Pedro.
2012/1/8 Matthew White <[email protected]>:
> Hi Pedro,
>
> Again, the mean is just one line:
>
> by day: generate mean = sum(x) / _n
>
> For the SD, I think the most efficient option is to use a program. See
> -help byable-:
>
> program runningsd, byable(recall, noheader)
> syntax varname, Generate(name)
> if _byindex() == 1 {
> confirm new variable `generate'
> quietly generate `generate' = .
> }
>
> if !_by() {
> local start 1
> local end = _N
> }
> else {
> local start = _byn1()
> local end = _byn2()
> }
>
> forvalues i = `start'/`end' {
> quietly summarize `varlist' in `start'/`i'
> quietly replace `generate' = r(sd) in `i'
> }
> end
>
> Then:
>
> by day: runningsd x, generate(sd)
>
> Best,
> Matt
>
> On Sun, Jan 8, 2012 at 3:23 PM, Pedro Nakashima
> <[email protected]> wrote:
>> Hi guys
>>
>> Unfortunately, I forgot one important point for my analysis.
>>
>> Given that I have the same kind of data for several days and I need to
>> calculate these statistics for each of these days, I have to do
>> something like "bysort days: 'all those commands' "
>>
>> Do you know how can I do that?
>>
>> One more time, best regards
>> Pedro
>>
>> 2012/1/8 Pedro Nakashima <[email protected]>:
>>> Perfect!
>>>
>>> Thank you Matthew and Sunil!
>>>
>>> Best,
>>> Pedro.
>>>
>>> 2012/1/8 Sunil Kumar <[email protected]>:
>>>> Does this achieve what you want?
>>>>
>>>> gen mean=.
>>>> gen sd=.
>>>>
>>>> local k=_N
>>>> forv i=1/`k' {
>>>> qui su x in 1/`i'
>>>> qui replace mean=r(mean) in `i'
>>>> qui replace sd=r(sd) in `i'
>>>> }
>>>>
>>>> Best,
>>>> Sunil
>>>> *
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>>
>> *
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>
>
>
> --
> Matthew White
> Data Coordinator
> Innovations for Poverty Action
> 101 Whitney Avenue, New Haven, CT 06510 USA
> +1 434-305-9861
> www.poverty-action.org
>
> *
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*
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