Steller, Antje (GQL-LM)
2009-Jul-06 11:14 UTC
[R] Counting the number of cycles in a temperature test
Hello dear R-users, today I have a question that I completely do not know how to solve (R-newbie!). In a temperature chamber I have measured temperature over time. The result is shown in the attached eps-file (if attachments are shown): There are two temperature levels, 150?C and -40?C. A complete cycle includes about 30 minutes upper temperature, quick change to the lower level, 30 minutes hold at lower level. Then the temperature rises again to the upper level and a new cycle begins. About 500 cycles have been completed. How can I count the number of cycles that have been completed? The data does not only include perfect temperature cycles. Once in a while the machine would stand still and for a day or so the temperature would remain at room temperature. So I cannot simply divide the measured time by the duration of a cycle... Thanks a lot for your support, if necessary I could also provide the dataset. Antje <<Temperaturzyklen.eps>>
You can count the number of times the values make a transition through some threshold and average over some short time period because you probably get multiple transitions in a short time as it is approaching the threshold. Once you have that, you can count then number of times it happens. On Mon, Jul 6, 2009 at 7:14 AM, Steller, Antje (GQL-LM)<antje.steller at volkswagen.de> wrote:> Hello dear R-users, > today I have a question that I completely do not know how to solve (R-newbie!). > > In a temperature chamber I have measured temperature over time. The result is shown in the attached eps-file (if attachments are shown): There are two temperature levels, 150?C and -40?C. A complete cycle includes about 30 minutes upper temperature, quick change to the lower level, 30 minutes hold at lower level. Then the temperature rises again to the upper level and a new cycle begins. About 500 cycles have been completed. > > How can I count the number of cycles that have been completed? > > The data does not only include perfect temperature cycles. Once in a while the machine would stand still and for a day or so the temperature would remain at room temperature. So I cannot simply divide the measured time by the duration of a cycle... > > Thanks a lot for your support, if necessary I could also provide the dataset. > > Antje > > > ?<<Temperaturzyklen.eps>> > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > >-- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem that you are trying to solve?
Moshe Olshansky
2009-Jul-08 00:20 UTC
[R] Counting the number of cycles in a temperature test
Hi Antje, Are your measurements taken every minute (i.e. 30 minutes correspond to 30 consecutive values)? How fast is your transition? If you had 30 minures of upper temperature, then 1000 minutes of room temperature and then 30 minutes of lower temperature - would you count this as a cycle? Can a cycle be 30 minutes of lower temperature followed by 30 minutes of upper temperature? --- On Mon, 6/7/09, Steller, Antje (GQL-LM) <antje.steller at volkswagen.de> wrote:> From: Steller, Antje (GQL-LM) <antje.steller at volkswagen.de> > Subject: [R] Counting the number of cycles in a temperature test > To: r-help at r-project.org > Received: Monday, 6 July, 2009, 9:14 PM > Hello dear R-users, > today I have a question that I completely do not know how > to solve (R-newbie!). > > In a temperature chamber I have measured temperature over > time. The result is shown in the attached eps-file (if > attachments are shown): There are two temperature levels, > 150?C and -40?C. A complete cycle includes about 30 > minutes upper temperature, quick change to the lower level, > 30 minutes hold at lower level. Then the temperature rises > again to the upper level and a new cycle begins. About 500 > cycles have been completed. > > How can I count the number of cycles that have been > completed? > > The data does not only include perfect temperature cycles. > Once in a while the machine would stand still and for a day > or so the temperature would remain at room temperature. So I > cannot simply divide the measured time by the duration of a > cycle... > > Thanks a lot for your support, if necessary I could also > provide the dataset. > > Antje > > > <<Temperaturzyklen.eps>> > > -----Inline Attachment Follows----- > > ______________________________________________ > R-help at r-project.org > mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, > reproducible code. >
Hi Antje, Say, if a cycle consists of an episode of high temperature and an episode of low temperature, you could count the end of these episodes, i.e. check how often your timeseries crosses an intermediate temperature. try: temperature <- sin(1:1000/10) # replace with your own previoustemperature <- c(temperature[-(1)], temperature[length(temperature)]) threshold <- 0.1 # replace with your own crossing <- ((temperature > threshold) != (previoustemperature > threshold)) crossingspercycle <- 2 cycles <- sum(crossing) / crossingspercycle Moshe Olshansky schreef:> Hi Antje, > > Are your measurements taken every minute (i.e. 30 minutes correspond to 30 consecutive values)? > How fast is your transition? > If you had 30 minures of upper temperature, then 1000 minutes of room temperature and then 30 minutes of lower temperature - would you count this as a cycle? > Can a cycle be 30 minutes of lower temperature followed by 30 minutes of upper temperature? > > --- On Mon, 6/7/09, Steller, Antje (GQL-LM) <antje.steller at volkswagen.de> wrote: > >> From: Steller, Antje (GQL-LM) <antje.steller at volkswagen.de> >> Subject: [R] Counting the number of cycles in a temperature test >> To: r-help at r-project.org >> Received: Monday, 6 July, 2009, 9:14 PM >> Hello dear R-users, >> today I have a question that I completely do not know how >> to solve (R-newbie!). >> >> In a temperature chamber I have measured temperature over >> time. The result is shown in the attached eps-file (if >> attachments are shown): There are two temperature levels, >> 150?C and -40?C. A complete cycle includes about 30 >> minutes upper temperature, quick change to the lower level, >> 30 minutes hold at lower level. Then the temperature rises >> again to the upper level and a new cycle begins. About 500 >> cycles have been completed. >> >> How can I count the number of cycles that have been >> completed? >> >> The data does not only include perfect temperature cycles. >> Once in a while the machine would stand still and for a day >> or so the temperature would remain at room temperature. So I >> cannot simply divide the measured time by the duration of a >> cycle... >> >> Thanks a lot for your support, if necessary I could also >> provide the dataset. >> >> Antje >> >> >> <<Temperaturzyklen.eps>> >> >> -----Inline Attachment Follows----- >> >> ______________________________________________ >> R-help at r-project.org >> mailing list >> https://stat.ethz.ch/mailman/listinfo/r-help >> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html >> and provide commented, minimal, self-contained, >> reproducible code. >> > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code.-- drs. H.A. (Arien) Lam (Ph.D. student) Department of Physical Geography Faculty of Geosciences Utrecht University, The Netherlands