I have been working with the base time series object (ts) and I had a couple of questions that hopefully this group can help me with: 1) What is the best why to append an observation to an existing time-series? Suppose I have a time series: t <- ts(1:12, frequency=5) This would generate two complete cycles and one remainder. Now I would like to append an observation to this time series. I could use 'c' but then I would need to rebuild the whole time series and I would need to know the frequency etc. I would like some operation like '+' that would simply append the value to the end of the time series (incrementing the 'las time value so thing like cycle() still output the correnct values) but alas t + 10 is already taken as an equally useful operation by adding 10 to each element in the time series (rather than in thie case, appending ts(10,frequency) with a time value of 13 to the time series). 2) How is the best way to get the last time value in a time series? I can do something like: (start(t)[2] - 1) + (end(t)[1]-1) * frequency(t) + end(t)[2] But there has to be an easier way. Thank you. Kevin
Time series (ts) questions.
2 messages · rkevinburton at charter.net, Gabor Grothendieck
Try this to append 100 to the end of the series, say: tt <- ts(1:12, frequency=5) # sample data ts(c(tt, 100), start = start(tt), frequency = frequency(tt))
On Mon, Sep 22, 2008 at 2:17 AM, <rkevinburton at charter.net> wrote:
I have been working with the base time series object (ts) and I had a couple of questions that hopefully this group can help me with: 1) What is the best why to append an observation to an existing time-series? Suppose I have a time series: t <- ts(1:12, frequency=5) This would generate two complete cycles and one remainder. Now I would like to append an observation to this time series. I could use 'c' but then I would need to rebuild the whole time series and I would need to know the frequency etc. I would like some operation like '+' that would simply append the value to the end of the time series (incrementing the 'las time value so thing like cycle() still output the correnct values) but alas t + 10 is already taken as an equally useful operation by adding 10 to each element in the time series (rather than in thie case, appending ts(10,frequency) with a time value of 13 to the time series). 2) How is the best way to get the last time value in a time series? I can do something like: (start(t)[2] - 1) + (end(t)[1]-1) * frequency(t) + end(t)[2] But there has to be an easier way. Thank you. Kevin
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