[R] Data handling

[arun]

Try:
 op <- options(digits.secs=4)

  TimeCC <- as.POSIXct(paste0(paste(teste[,1],teste[,2]), sub("^0","",teste[,3])),format="%m/%d/%y %H:%M:%OS")
options(op) #reset

A.K.


On Tuesday, October 15, 2013 10:29 AM, Raoni Rodrigues <caciquesamurai at gmail.com> wrote:
Hello all,

I'm having a problem with data handling. My input data is (dput in the
after the signature):

    Date     Time Fraction
06/19/13 22:15:39   0.3205
06/19/13 22:15:44   0.3205
06/19/13 22:15:49   0.3205
06/19/13 22:15:54   0.3205
06/19/13 22:15:59   0.3205
06/19/13 22:16:09   0.3205

Date in format month/day/year, Time in HH:MM:SS and fraction represents the
fractions of seconds. I need to have a vector in a format year-month-day
hh:mm:ss.0000. Or, in format: format = "%F %H:%M:%OS4", as POSIXct class.

I made the the conversion step-by-step to have sure that nothing is missed
in the way:

> options (digits.sec = 4)
> getOption ("digits.sec")
[1] 4
> teste$Date1 = as.Date (teste$Date, format = "%m/%d/%y")
> class (teste$Date1)
[1] "Date"
> teste$Fraction = sub ("0.", "", teste$Fraction)
> teste$TimeC = paste (teste$Time, teste$Fraction, sep = ".")
> teste$TimeCC = paste (teste$Date1, teste$TimeC)

> head (teste)
      Date     Time Fraction      Date1        TimeC                  TimeCC
1 06/19/13 22:15:39     .325 2013-06-19 22:15:39.325 2013-06-19
22:15:39.3205
2 06/19/13 22:15:44     .325 2013-06-19 22:15:44.325 2013-06-19
22:15:44.3205
3 06/19/13 22:15:49     .325 2013-06-19 22:15:49.325 2013-06-19
22:15:49.3205
4 06/19/13 22:15:54     .325 2013-06-19 22:15:54.325 2013-06-19
22:15:54.3205
5 06/19/13 22:15:59     .325 2013-06-19 22:15:59.325 2013-06-19
22:15:59.3205
6 06/19/13 22:16:09     .325 2013-06-19 22:16:09.325 2013-06-19
22:16:09.3205

So far so well. The problem is when I tried to convert to POSIXct class. If
I use just:

teste$TimeCC = format (teste$TimeCC, format = "%F %H:%M:%OS4")
teste$TimeCC = as.POSIXct (teste$TimeCC)

I lost the fraction of seconds. If I use:

teste$TimeCC = as.POSIXct(strptime (teste$TimeCC, format = "%F %H:%M:%OS4"))

I lost all information and get just <NA>.

Thanks in advanced,

-- 
Raoni Rosa Rodrigues
Research Associate of Fish Transposition Center CTPeixes
Universidade Federal de Minas Gerais - UFMG
Brasil
rodrigues.raoni at gmail.com

dput of input data

structure(list(Date = c("06/19/13", "06/19/13", "06/19/13", "06/19/13",
"06/19/13", "06/19/13"), Time = c("22:15:39", "22:15:44", "22:15:49",
"22:15:54", "22:15:59", "22:16:09"), Fraction = c("0.3205", "0.3205",
"0.3205", "0.3205", "0.3205", "0.3205")), .Names = c("Date",
"Time", "Fraction"), row.names = c(NA, 6L), class = "data.frame")

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