[R] datetime on x-axis of plot

[Steve Revilak]

> From: joshv

> Hello, I'm reading Time Series Analysis and its Applilcations with R Examples
> and I have a question...
> 
> I notice that in the book there are timeseries plots but without the x-axis
> being labeled with dates.  They are just numbers 1,...50,...100, etc.  How
> do I get the date to show up on the x-axis?
> 
> Here is my dateframe:
> 
> > head(myData, 5)
> 
> 1 2008-01-30 08:30   7.00
> 2 2008-01-30 08:32   9.25
> 3 2008-01-30 08:34   5.50
> 4 2008-01-30 08:36   5.00
> 5 2008-01-30 08:38 -26.25

Try this:

   # "foo.dat" is a two-column file with the data you gave earlier
   myData <- read.table("foo.dat", sep="\t", colClasses=c("POSIXct", "numeric"))

   # plot, but don't label the x-axis
   plot(myData, type="l", xaxt="n")

   # now, add labels to the x-axis
   axis.POSIXct(1, myData$V1, format="%m/%d %H:%M")

Steve