?tapply
temp.data<-data[as.character(data$time %in%
c("02:00","03:00","04:00"),]
# one quick and dirty method is to create a subset the data , not sure what
format your time data is so converted to character strings.
then something like:
tapply(temp.data$V1, factor(temp.data$time), mean)
Wayne
-----Original Message-----
From: r-help-bounces at r-project.org
[mailto:r-help-bounces at r-project.org]On Behalf Of jerzack
Sent: 13 September 2007 10:26
To: r-help at stat.math.ethz.ch
Subject: [R] pick time intervalls
Hello,
as an R beginner I have a question concerning the following data set:
nr date time V1 V2 V3 V4 V5 V6
...
2828 26/08/05 20:00 60 38 55 58 53 56
2829 26/08/05 21:00 58 34 54 49 45 53
2830 26/08/05 22:00 56 35 52 51 46 47
2831 26/08/05 23:00 56 35 50 45 46 38
2832 27/08/05 00:00 61 34 49 42 47 32
2833 27/08/05 01:00 62 38 52 49 48 36
2834 27/08/05 02:00 64 39 51 49 50 42
2835 27/08/05 03:00 63 40 49 46 49 33
2836 27/08/05 04:00 58 37 47 48 51 20
...
How can I access values at a certain time intervall every day.
For example I would like to calculate the mean of the V1 values for the
times 02:00 - 04:00 every day.
Thank you very much for your help!
jeremy
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