Re: [R] Selecting timestamps

From: <Bill.Venables_at_csiro.au>
Date: Thu, 21 Feb 2008 17:40:00 +1000

Since both sequences are in hourly steps, there is a fairly easy way to do this:

> before <- colSums(outer(seq1, seq2, "<")) > sort(c(seq1[before], seq1[before+1]))

This uses the fact that both sequences are in hourly time steps, so the time stamp 'just after' the member of seq2 is the next one to the one 'just before'. Relaxing this assumption, if needed, is left as an easy exercise.

Bill Venables

-----Original Message-----
From: r-help-bounces_at_r-project.org [mailto:r-help-bounces_at_r-project.org] On Behalf Of Lauri Nikkinen
Sent: Thursday, 21 February 2008 5:04 PM To: r-help_at_stat.math.ethz.ch
Subject: [R] Selecting timestamps

R-users,

I have two vectors (of timestamps)

d1 <- as.POSIXct(strptime("2.2.2002 07:00", format="%d.%m.%Y %H:%M"))
d2 <- as.POSIXct(strptime("4.2.2002 07:00", format="%d.%m.%Y %H:%M"))
seq1 <- seq(d1, d2, "hours")

seq1
d3 <- as.POSIXct(strptime("2.2.2002 15:22", format="%d.%m.%Y %H:%M"))
d4 <- as.POSIXct(strptime("3.2.2002 18:12", format="%d.%m.%Y %H:%M"))
seq2 <- seq(d3, d4, "hours")

seq2

How to select timestamps from seq1 which are just before and after of particular timestamp in seq2?
The resulting vector should look like this in this example:

"2002-02-02 15:00:00 Normaaliaika"
"2002-02-02 16:00:00 Normaaliaika"
"2002-02-02 16:00:00 Normaaliaika"
"2002-02-02 17:00:00 Normaaliaika"
"2002-02-02 17:00:00 Normaaliaika"
"2002-02-02 18:00:00 Normaaliaika"
"2002-02-02 18:00:00 Normaaliaika"
etc.

Thank you,
Lauri

> sessionInfo()
R version 2.6.0 (2007-10-03)
i386-pc-mingw32

locale:
LC_COLLATE=Finnish_Finland.1252;LC_CTYPE=Finnish_Finland.1252;LC_MONETAR Y=Finnish_Finland.1252;LC_NUMERIC=C;LC_TIME=Finnish_Finland.1252

attached base packages:
[1] stats graphics grDevices utils datasets methods base

other attached packages:
[1] RODBC_1.2-3 loaded via a namespace (and not attached): [1] tools_2.6.0



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. Received on Thu 21 Feb 2008 - 07:49:02 GMT

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.2.0, at Thu 21 Feb 2008 - 11:30:16 GMT.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help. Please read the posting guide before posting to the list.

list of date sections of archive