[R] Double condition

[Rui Barradas]

Hello,

Try the following.


idx <- which(subz$fix == "noon")
if(idx[length(idx)] == nrow(subz)) idx <- idx[-length(idx)]
subz$day[idx + 1] <- subz$day[idx]


Hope this helps,

Rui Barradas

Em 22-03-2013 18:18, zuzana zajkova escreveu:
> 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
>
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>
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