I have a set of timestamp data that I have in a text file that I would like to import into R for analysis. The timestamps are formated as follows: DT_1,DT_2 [2006/08/10 21:12:14 ],[2006/08/10 21:54:00 ] [2006/08/10 20:42:00 ],[2006/08/10 22:48:00 ] [2006/08/10 20:58:00 ],[2006/08/10 21:39:00 ] [2006/08/04 12:15:24 ],[2006/08/04 12:20:00 ] [2006/08/04 12:02:00 ],[2006/08/04 14:20:00 ] I can get them into R but I cannot figure out how to convert them into something R will recognize as a date/time. I have tried using "as.Date", strptime, and chron. Any help would be appreciated? best, Spencer On 1/4/07, Darin A. England <england@cs.umn.edu> wrote:> > > Does anyone know a reason why, in principle, a call to randomForest > cannot accept a data frame with missing predictor values? If each > individual tree is built using CART, then it seems like this > should be possible. (I understand that one may impute missing values > using rfImpute or some other method, but I would like to avoid doing > that.) > > If this functionality were available, then when the trees are being > constructed and when subsequent data are put through the forest, one > would also specify an argument for the use of surrogate rules, just > like in rpart. > > I realize this question is very specific to randomForest, as opposed > to R in general, but any comments are appreciated. I suppose I am > looking for someone to say "It's not appropriate, and here's why > ..." or "Good idea. Please implement and post your code." > > Thanks, > > Darin England, Senior Scientist > Ingenix > > ______________________________________________ > R-help@stat.math.ethz.ch 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]]
Try this:
Lines <- "DT_1,DT_2
[2006/08/10 21:12:14 ],[2006/08/10 21:54:00 ]
[2006/08/10 20:42:00 ],[2006/08/10 22:48:00 ]
[2006/08/10 20:58:00 ],[2006/08/10 21:39:00 ]
[2006/08/04 12:15:24 ],[2006/08/04 12:20:00 ]
[2006/08/04 12:02:00 ],[2006/08/04 14:20:00 ]
"
Lines2 <- gsub("\\[|\\]", "",
readLines(textConnection(Lines)))
# using chron
library(chron)
DT <- read.csv(textConnection(Lines2))
DT[] <- lapply(DT, function(x)
chron(substring(x, 1, 10), substring(x, 12), format = c("Y/M/D",
"h:m:s")))
DT
# using POSIXct
DT <- read.csv(textConnection(Lines2))
DT[] <- lapply(DT, as.POSIXct)
DT
On 1/4/07, sj <ssj1364 at gmail.com> wrote:> I have a set of timestamp data that I have in a text file that I would like
> to import into R for analysis.
> The timestamps are formated as follows:
>
> DT_1,DT_2
> [2006/08/10 21:12:14 ],[2006/08/10 21:54:00 ]
> [2006/08/10 20:42:00 ],[2006/08/10 22:48:00 ]
> [2006/08/10 20:58:00 ],[2006/08/10 21:39:00 ]
> [2006/08/04 12:15:24 ],[2006/08/04 12:20:00 ]
> [2006/08/04 12:02:00 ],[2006/08/04 14:20:00 ]
>
> I can get them into R but I cannot figure out how to convert them into
> something R will recognize as a date/time. I have tried using
"as.Date",
> strptime, and chron. Any help would be appreciated?
>
> best,
>
> Spencer
>
>
>
> On 1/4/07, Darin A. England <england at cs.umn.edu> wrote:
> >
> >
> > Does anyone know a reason why, in principle, a call to randomForest
> > cannot accept a data frame with missing predictor values? If each
> > individual tree is built using CART, then it seems like this
> > should be possible. (I understand that one may impute missing values
> > using rfImpute or some other method, but I would like to avoid doing
> > that.)
> >
> > If this functionality were available, then when the trees are being
> > constructed and when subsequent data are put through the forest, one
> > would also specify an argument for the use of surrogate rules, just
> > like in rpart.
> >
> > I realize this question is very specific to randomForest, as opposed
> > to R in general, but any comments are appreciated. I suppose I am
> > looking for someone to say "It's not appropriate, and
here's why
> > ..." or "Good idea. Please implement and post your
code."
> >
> > Thanks,
> >
> > Darin England, Senior Scientist
> > Ingenix
> >
> > ______________________________________________
> > R-help at stat.math.ethz.ch 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 at stat.math.ethz.ch 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.
>
Suppose that you have the timestamps in a comma seperated text file,
"times.dat" then do
tid <- read.csv("times.dat", header = TRUE, colClasses =
"character")
# Note the colClasses argument! If not used the columns of tid are factors by
default.
time.conv <- function(x) as.POSIXct(strptime(x, format = "[%Y/%m/%d
%H:%M:%S ]"))
# The value of strptime has class "POSIXlt" and needs to be converted
to "POSIXct"
tid2 <- tid
for (i in 1:2) tid2[,i] <- time.conv(tid2[,i])
print(tid2)
str(tid2)
class(tid2[,1])
Med venlig hilsen
Frede Aakmann T?gersen
> -----Oprindelig meddelelse-----
> Fra: r-help-bounces at stat.math.ethz.ch
> [mailto:r-help-bounces at stat.math.ethz.ch] P? vegne af sj
> Sendt: 4. januar 2007 22:39
> Til: r-help at stat.math.ethz.ch
> Emne: [R] importing timestamp data into R
>
> I have a set of timestamp data that I have in a text file
> that I would like to import into R for analysis.
> The timestamps are formated as follows:
>
> DT_1,DT_2
> [2006/08/10 21:12:14 ],[2006/08/10 21:54:00 ] [2006/08/10
> 20:42:00 ],[2006/08/10 22:48:00 ] [2006/08/10 20:58:00
> ],[2006/08/10 21:39:00 ]
> [2006/08/04 12:15:24 ],[2006/08/04 12:20:00 ]
> [2006/08/04 12:02:00 ],[2006/08/04 14:20:00 ]
>
> I can get them into R but I cannot figure out how to convert
> them into something R will recognize as a date/time. I have
> tried using "as.Date", strptime, and chron. Any help would be
> appreciated?
>
> best,
>
> Spencer
>
>
>
> On 1/4/07, Darin A. England <england at cs.umn.edu> wrote:
> >
> >
> > Does anyone know a reason why, in principle, a call to randomForest
> > cannot accept a data frame with missing predictor values? If each
> > individual tree is built using CART, then it seems like
> this should be
> > possible. (I understand that one may impute missing values using
> > rfImpute or some other method, but I would like to avoid doing
> > that.)
> >
> > If this functionality were available, then when the trees are being
> > constructed and when subsequent data are put through the
> forest, one
> > would also specify an argument for the use of surrogate rules, just
> > like in rpart.
> >
> > I realize this question is very specific to randomForest,
> as opposed
> > to R in general, but any comments are appreciated. I suppose I am
> > looking for someone to say "It's not appropriate, and
> here's why ..."
> > or "Good idea. Please implement and post your code."
> >
> > Thanks,
> >
> > Darin England, Senior Scientist
> > Ingenix
> >
> > ______________________________________________
> > R-help at stat.math.ethz.ch 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 at stat.math.ethz.ch 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.
>