I couldn't find anything in the chron or timeDate packages, and a good
search
yielded rounding to the nearest half hour, which I don't want.
The data:
structure(list(Date = structure(c(1209625080, 1209641460, 1209652500,
1209676800, 1209682860, 1209692100, 1209706980, 1209722580, 1209726300,
1209739620, 1209762780, 1209765720, 1209770520, 1209791040, 1209812580,
1209829920, 1209837180, 1209848160, 1209854640, 1209859440, 1209870780,
1209887760, 1209901080, 1209921660, 1209929280, 1209945600, 1209957240,
1209980280, 1210001760, 1210017000, 1210021140, 1210034820, 1210042800,
1210048980, 1210061520, 1210074480, 1210081200, 1210089300, 1210095960,
1210104120, 1210110900, 1210110900, 1210118400, 1210126980, 1210134180,
1210142640, 1210156080, 1210164180, 1210176840, 1210183740), class
c("POSIXct",
"POSIXt"), tzone = ""), Score = c(80L, 11L, 81L, 152L, 130L,
122L, 142L, 20L, 1L, 31L, 93L, 136L, 128L, 112L, 48L, 57L, 92L,
108L, 100L, 107L, 81L, 37L, 47L, 70L, 114L, 125L, 99L, 46L, 108L,
106L, 111L, 75L, 75L, 136L, 36L, 13L, 35L, 71L, 105L, 113L, 116L,
116L, 94L, 130L, 102L, 19L, 1L, 33L, 78L, 89L)), .Names = c("Date",
"Score"), row.names = c(NA, 50L), class = "data.frame")
I'm trying to round the time down to the nearest half hour, without losing
the date. For example, 01/01/2009 1:29 would round to 01/01/2009 1:00,
while 01/01/2009 1:31 would round to 01/01/2009 1:30.
Any help is greately appreciated.
--
View this message in context:
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Sent from the R help mailing list archive at Nabble.com.
Rainer Schuermann
2012-Jul-20 05:07 UTC
[R] Truncating (rounding down) to nearest half hour.
My amateur approach: I put your data in a dataframe called t:> head( t )Date Score 1 2008-05-01 08:58:00 80 2 2008-05-01 13:31:00 11 3 2008-05-01 16:35:00 81 4 2008-05-01 23:20:00 152 5 2008-05-02 01:01:00 130 6 2008-05-02 03:35:00 122 Then I created a vector with rounded down minutes:> minutes <- floor( as.numeric( substr( t[,1], 15, 16 ) ) / 30 ) * 30 > minutes <- ifelse( minutes == 30, "30", "00" ) > head( minutes )[1] "30" "30" "30" "00" "00" "30" Next the replacement:> tc <- t > tc[,1] <- as.character( t[,1] ) > substr( tc[,1] , 15, 16 ) <- minutes > tc[,1] <- as.POSIXct( tc[,1] ) > head( tc )Date Score 1 2008-05-01 08:30:00 80 2 2008-05-01 13:30:00 11 3 2008-05-01 16:30:00 81 4 2008-05-01 23:00:00 152 5 2008-05-02 01:00:00 130 6 2008-05-02 03:30:00 122 Is that what you were looking for? Rgds, Rainer -------- Original-Nachricht --------> Datum: Thu, 19 Jul 2012 10:03:23 -0700 (PDT) > Von: APOCooter <mikeedinger16 at gmail.com> > An: r-help at r-project.org > Betreff: [R] Truncating (rounding down) to nearest half hour.> I couldn't find anything in the chron or timeDate packages, and a good > search > yielded rounding to the nearest half hour, which I don't want. > > The data: > > structure(list(Date = structure(c(1209625080, 1209641460, 1209652500, > 1209676800, 1209682860, 1209692100, 1209706980, 1209722580, 1209726300, > 1209739620, 1209762780, 1209765720, 1209770520, 1209791040, 1209812580, > 1209829920, 1209837180, 1209848160, 1209854640, 1209859440, 1209870780, > 1209887760, 1209901080, 1209921660, 1209929280, 1209945600, 1209957240, > 1209980280, 1210001760, 1210017000, 1210021140, 1210034820, 1210042800, > 1210048980, 1210061520, 1210074480, 1210081200, 1210089300, 1210095960, > 1210104120, 1210110900, 1210110900, 1210118400, 1210126980, 1210134180, > 1210142640, 1210156080, 1210164180, 1210176840, 1210183740), class > c("POSIXct", > "POSIXt"), tzone = ""), Score = c(80L, 11L, 81L, 152L, 130L, > 122L, 142L, 20L, 1L, 31L, 93L, 136L, 128L, 112L, 48L, 57L, 92L, > 108L, 100L, 107L, 81L, 37L, 47L, 70L, 114L, 125L, 99L, 46L, 108L, > 106L, 111L, 75L, 75L, 136L, 36L, 13L, 35L, 71L, 105L, 113L, 116L, > 116L, 94L, 130L, 102L, 19L, 1L, 33L, 78L, 89L)), .Names = c("Date", > "Score"), row.names = c(NA, 50L), class = "data.frame") > > I'm trying to round the time down to the nearest half hour, without losing > the date. For example, 01/01/2009 1:29 would round to 01/01/2009 1:00, > while 01/01/2009 1:31 would round to 01/01/2009 1:30. > > Any help is greately appreciated. > > -- > View this message in context: > http://r.789695.n4.nabble.com/Truncating-rounding-down-to-nearest-half-hour-tp4637083.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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.-- ------- Gentoo Linux with KDE