It sounds like, although your "noon" and "midnight" data are separate rows, they are not fully independent. If I understand correctly, the operation you want to perform would be simple if you had (at least temporarily) a single row with columns ddawn.midnight, ddusk.midnight, ddawn.noon, ddusk.noon, rather than two separate rows.
I recommend you check out the reshape package http://had.co.nz/reshape/, and read the paper Hadley wrote about it for a conceptual understanding of wide vs. long data. On Fri, Mar 22, 2013 at 11:18 AM, zuzana zajkova <zuzu...@gmail.com> wrote: > Hi, > > I would appreciate if somebody could help me with this small issue... > I have a dataframe like this (originaly has more than 100 000 rows): > > > subz > jul time dtime fix ddawn ddusk day > 101608 15006 2011-02-01 19:14:49 19.24694 noon 7.916667 19.88333 1 > 101609 15006 2011-02-01 19:24:49 19.41361 midnight 7.916667 19.56667 1 > 101610 15006 2011-02-01 19:24:49 19.41361 noon 7.916667 19.88333 1 > 101611 15006 2011-02-01 19:34:49 19.58028 midnight 7.916667 19.56667 0 > 101612 15006 2011-02-01 19:34:49 19.58028 noon 7.916667 19.88333 1 > 101613 15006 2011-02-01 19:44:49 19.74694 midnight 7.916667 19.56667 0 > 101614 15006 2011-02-01 19:44:49 19.74694 noon 7.916667 19.88333 1 > 101615 15006 2011-02-01 19:54:49 19.91361 midnight 7.916667 19.56667 0 > 101616 15006 2011-02-01 19:54:49 19.91361 noon 7.916667 19.88333 0 > 101617 15006 2011-02-01 20:04:49 20.08028 midnight 7.916667 19.56667 0 > 101618 15006 2011-02-01 20:04:49 20.08028 noon 7.916667 19.88333 0 > > > dput(subz) > structure(list(jul = c(15006, 15006, 15006, 15006, 15006, 15006, > 15006, 15006, 15006, 15006, 15006), time = structure(c(1296587689, > 1296588289, 1296588289, 1296588889, 1296588889, 1296589489, 1296589489, > 1296590089, 1296590089, 1296590689, 1296590689), class = c("POSIXct", > "POSIXt"), tzone = "GMT"), dtime = c(19.2469444444444, 19.4136111111111, > 19.4136111111111, 19.5802777777778, 19.5802777777778, 19.7469444444444, > 19.7469444444444, 19.9136111111111, 19.9136111111111, 20.0802777777778, > 20.0802777777778), fix = structure(c(2L, 1L, 2L, 1L, 2L, 1L, > 2L, 1L, 2L, 1L, 2L), .Label = c("midnight", "noon"), class = "factor"), > ddawn = c(7.91666666666667, 7.91666666666667, 7.91666666666667, > 7.91666666666667, 7.91666666666667, 7.91666666666667, 7.91666666666667, > 7.91666666666667, 7.91666666666667, 7.91666666666667, 7.91666666666667 > ), ddusk = c(19.8833333333333, 19.5666666666667, 19.8833333333333, > 19.5666666666667, 19.8833333333333, 19.5666666666667, 19.8833333333333, > 19.5666666666667, 19.8833333333333, 19.5666666666667, 19.8833333333333 > ), day = c(1, 1, 1, 0, 1, 0, 1, 0, 0, 0, 0)), .Names = c("jul", > "time", "dtime", "fix", "ddawn", "ddusk", "day"), row.names = > 101608:101618, class = "data.frame") > > where "day" is calculated as > > subz$day <- ifelse( subz$dtime > subz$ddusk | subz$dtime < subz$ddawn, 0, 1 > ) > > The way I would like to calculate "day" is this > - for the same "time", the "day" is calculated for "noon" as mentioned > above but for "midnight" is just copying the same value as for "noon". > So for the same "time" the "day" value should be the same for "noon" and > "midnight". > Something like this: > > jul time dtime fix ddawn ddusk day > 101608 15006 2011-02-01 19:14:49 19.24694 noon 7.916667 19.88333 1 > 101609 15006 2011-02-01 19:24:49 19.41361 midnight 7.916667 19.56667 1 > 101610 15006 2011-02-01 19:24:49 19.41361 noon 7.916667 19.88333 1 > 101611 15006 2011-02-01 19:34:49 19.58028 midnight 7.916667 19.56667 1 > 101612 15006 2011-02-01 19:34:49 19.58028 noon 7.916667 19.88333 1 > 101613 15006 2011-02-01 19:44:49 19.74694 midnight 7.916667 19.56667 1 > 101614 15006 2011-02-01 19:44:49 19.74694 noon 7.916667 19.88333 1 > 101615 15006 2011-02-01 19:54:49 19.91361 midnight 7.916667 19.56667 0 > 101616 15006 2011-02-01 19:54:49 19.91361 noon 7.916667 19.88333 0 > 101617 15006 2011-02-01 20:04:49 20.08028 midnight 7.916667 19.56667 0 > 101618 15006 2011-02-01 20:04:49 20.08028 noon 7.916667 19.88333 0 > > Where I get stuck, is I don't know how to get the value for "midnight". > > Any suggestion is welcome. Thanks > > Zuzana > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@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. > [[alternative HTML version deleted]] ______________________________________________ R-help@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.
