Combining date and time into a Date column for plotting

Question

I want to create a line plot. I have 3 columns in my data frame:

date        time   numbers
01-02-2010  14:57  5
01-02-2010  23:23  7
02-02-2010  05:05  3
02         


        

Answer 1

Reconstruct your data:

dat <- read.table(text="
date        time   numbers
01-02-2010  14:57  5
01-02-2010  23:23  7
02-02-2010  05:05  3
02-02-2010  10:23  11", header=TRUE)

Now use as.POSIXct() and paste() to combine your date and time into a POSIX date. You need to specify the format, using the symbols defined in ?strptime. Also see ?DateTimeClasses for more information

dat$newdate <- with(dat, as.POSIXct(paste(date, time), format="%m-%d-%Y %H:%M"))
plot(numbers ~ newdate, data=dat, type="b", col="blue")