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.stel...@volkswagen.de> wrote:
From: Steller, Antje (GQL-LM) <antje.stel...@volkswagen.de>
Subject: [R] Counting the number of cycles in a temperature test
To: r-help@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-----
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