Great !!
It sounds perfect to me, I will give it a try and let you know.
Thanks a bunch : )
Diego
--- Lun 7/12/09, Eric Booth <[email protected]> ha scritto:
> Da: Eric Booth <[email protected]>
> Oggetto: Re: st: Summarizing data by Timestamps
> A: [email protected]
> Data: Lunedì 7 dicembre 2009, 20:19
> ><
> >
>
> Diego:
>
> I added some extra timestamps since you were interested in
> time periods of a couple of hours:
>
>
> ****
> clear
>
> input str20 timestamp
> pressure
> "11/22/09 00:00" 120
> "11/22/09 00:01" 123
> "11/22/09 00:02" 119
> "11/22/09 00:03" 115
> "11/22/09 00:09" 123
> "11/22/09 00:10" 122
> "11/22/09 00:22" 112
> "11/22/09 01:20" 2000
> "11/22/09 01:27" 2100
> "11/22/09 05:27"
> 5000
> "11/22/09 06:45"
> 10000
> end
>
> *format timestamp %tCNNDDYY_HH:MM
> g double timestamp2 = clock(timestamp, "MD20Yhm")
>
> **avg. by one hour interval**
> g hour = hh(timestamp2)
> egen one_hour_avg = mean(pressure), by(hour)
>
> **take averages for different time periods from 1:00**
> forv t = 2(1)6 {
> egen hour_avg_`t' = mean(pressure)if hour<=(1+`t') &
> hour>=1
> }
>
> **or by collapse to get summary info by hour, etc**
> preserve
> collapse (mean) pressure , by(hour)
> li
> restore
> *****
>
>
> ~Eric
> __
> Eric A. Booth
> Public Policy Research Institute
> Texas A&M University
> [email protected]
> Office: +979.845.6754
>
>
>
> On Dec 7, 2009, at 12:51 PM, Diego Bellavia wrote:
>
> > Hello StataListers,
> >
> > I have such a dataset:
> >
> > Timestamp
> Pressure
> > 11/22/09 00:00 120
> > 11/22/09 00:01 123
> > 11/22/09 00:02 119
> > 11/22/09 00:03 115
> > 11/22/09 00:09 123
> > 11/22/09 00:10 122
> > 11/22/09 00:22 112
> >
> > etc...
> >
> > As you see, Pressure values are reported by time
> (defined as a timestamp) every minute.
> > Unfortunately, the system is not so precise to collect
> pressure every single minute so,
> > I do not necessarily have 60 measures in 1 hour.
> > Now I would like to compute averages for Pressure
> every pre-spcified time range, starting, as exmaple,
> > with ana average of all the values collected between
> 00:00 and 01:00 on 11/22/2009 but also being able to
> > change the time range from 1 hour, to 4 or 6 hours and
> so on.
> >
> > How can I do that in STATA, considering that I do not
> know how many measure are collected per hour ?
> >
> > Thank you in advance,
> >
> > Diego
> >
> >
> >
> >
>
>
>
> *
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>
*
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