I have a dataset with a very simple logfile-like structure, I want to subset the data according to date ranges but can only do on one parameter.
my data looks like this:
date_time loc_id node energy kgco2
1 2009-02-27 00:11:08 87 103 0.00000 0.00000
2 2009-02-27 01:05:05 87 103 7.00000 3.75900
3 2009-02-27 02:05:05 87 103 6.40039 3.43701
4 2009-02-27 03:05:05 87 103 4.79883 2.57697
5 2009-02-27 04:05:05 87 103 4.10156 2.20254
6 2009-02-27 05:05:05 87 103 2.59961 1.39599
the file includes data for a a whole year, I want to create summary plots for every month and perhaps week
I am processing the date_time as follows:
> dt <-as.POSIXlt(ae$date_time)
> ae$dt <- dt
> names(ae$dt)
[1] "sec" "min" "hour" "mday" "mon" "year" "wday" "yday" "isdst"
now I'm trying to subset the data as:
> x <- ae$energy[ae$dt$year=="110" & ae$dt$mon=="10"]
> x
numeric(0)
"110" is because the following:
> range(ae$dt$year)
[1] 109 110
I have also tried the following with no luck:
> d <- subset(ae, (dt$year=="110" & dt$mon=="10"), select=energy)
these however do work:
> d <- subset(ae, dt$year=="110", select=energy)
and so does this
> d <- subset(ae, dt$mon=="10", select=energy)
any ideas on how can I subset by selecting both year and month?
Thanks,
Best Answer
ok timeseries seem to have done the trick: