Fantastic, that works fantastically. Is there a optimal way to search R
News topics, so that I can catch references like this? For all my searching
of list serves, and documentation, I found very little which could help me.
I have however, had excellent help with R-help, Gabor, I appreciate your
response very much.
Pat
On Tue, Aug 18, 2009 at 5:18 AM, Gabor Grothendieck <ggrothendi...@gmail.com
> wrote:
> Try this:
>
>
> Lines <- '"1","30 Jun 2009 18:14:59"
> "2","02 Jul 2009 07:33:37"
> "3","06 Jul 2009 08:22:35"
> "4","06 Jul 2009 19:25:50"
> "5","08 Jul 2009 08:41:48"
> "6","10 Jul 2009 07:31:39"
> "7","10 Jul 2009 19:59:25"
> "8","13 Jul 2009 07:49:18"
> "9","13 Jul 2009 18:52:52"
> "10","15 Jul 2009 08:06:56"
> "11","15 Jul 2009 19:03:01"
> "12","17 Jul 2009 08:02:02"'
>
> library(chron)
> DF <- read.csv(textConnection(Lines), header = FALSE, as.is = TRUE)
> dd <- as.chron(DF$V2, "%d %b %Y %H:%M:%S")
>
> dd - dates(dd) > times("12:00:00") # c(TRUE, FALSE, ...)
>
>
> See R News 4/1 and its references for more.
>
>
> On Tue, Aug 18, 2009 at 3:42 AM, Pat Schmitz<pschm...@illinois.edu> wrote:
> > R-Help
> >
> > I have a data set which uses a DateTime string as follows : "2009-06-30
> > 18:14:59"
> > While I have been able to convert to DateTime properly
> >
> > time <- strptime(as.character(dat$Time),format='%d %b %Y %T') #Convert to
> > dateTime string
> >
> > I would like to use the time of day "hour" as a *factor* level. I have
> > found that I can convert the date time to a factor
> >
> > time <- as.ordered(cut(time, "hour"))
> >
> > But this produces a factor level for every single day. The issue I have
> is
> > in figuring out how to apply a logical statement to the datetime string
> or
> > to the factor. I would like to say that every datetime with an hour <12
> is
> > the morning factor, and every datetime with an hour >12 is at night.
> Without
> > LOTS of superfluous code. below I am going as far as splitting the
> string
> > to columns, pulling the time and then setting the factor with a for
> > statement...yeesh. I have example CSV dates at the end.
> >
> > new.dates <- matrix(unlist(lapply(as.character(dat$Time), function(x)
> > strsplit(x," "))),ncol=4, byrow=TRUE) #Break Time String into columns
> > colnames(new.dates) <- c("day","month","year", "time") # Set column names
> > dat <- cbind(as.data.frame(new.dates), as.data.frame(dat)) #bind to data
> > frame
> >
> > tfact<-matrix()
> >
> > for (i in which(as.character(dat$time) <= "12:00:00")){
> > tfact[i] <- "Morning"
> > }
> >
> > for (i in which(as.character(dat$time) >= "12:00:00")){
> > tfact[i] <- "Night"
> > }
> >
> > tfact<-factor(tfact,
> > levels=c("Morning", "Night"),
> > )
> >
> > Example CSV Data
> > "1","30 Jun 2009 18:14:59"
> > "2","02 Jul 2009 07:33:37"
> > "3","06 Jul 2009 08:22:35"
> > "4","06 Jul 2009 19:25:50"
> > "5","08 Jul 2009 08:41:48"
> > "6","10 Jul 2009 07:31:39"
> > "7","10 Jul 2009 19:59:25"
> > "8","13 Jul 2009 07:49:18"
> > "9","13 Jul 2009 18:52:52"
> > "10","15 Jul 2009 08:06:56"
> > "11","15 Jul 2009 19:03:01"
> > "12","17 Jul 2009 08:02:02"
> >
> >
> > Thanks
> > Pat
> >
> > --
> > Patrick Schmitz
> > Graduate Student
> > Plant Biology
> > 1206 West Gregory Drive
> > RM 1500
> >
> > [[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.
> >
>
--
Patrick Schmitz
Graduate Student
Plant Biology
1206 West Gregory Drive
RM 1500
[[alternative HTML version deleted]]
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