[R] Line plot with date-time on X-axis

[Michael A. Miller]

>>>>> "Malladi," == Malladi, Sukhaswami <smalladi at lexgen.com> writes:

    > Dear List, What is the way in R to plot a graph having date
    > time (e.g. format 12/31/2002 13:12) in the x axis and
    > numerical value (e.g. temperature) on the Y-axis ?

I tend to use chron for that sort of thing.

Mike

> df
        date     time temp
1 2002/08/09 12:15:00   98
2 2002/08/09 13:15:00   95
3 2002/08/09 14:15:00   94
4 2002/08/08 15:15:00   90
5 2002/08/08 16:15:00   88
6 2002/08/08 17:15:00   80
7 2002/08/08 18:15:00   71
8 2002/08/08 19:15:00   76

> library(chron)
> df$datetime <- chron(dates=as.character(df$date),
                       times=df$time,format=c('y/m/d', 'h:m:s')) # date and time
> df$dates <- dates(df$datetime) # just the dates, with no time
> df$times <- times(df$time) # just the times, independent of date
> 
> df
        date     time temp            datetime    dates    times
1 2002/08/09 12:15:00   98 (02/08/09 12:15:00) 08/09/02 12:15:00
2 2002/08/09 13:15:00   95 (02/08/09 13:15:00) 08/09/02 13:15:00
3 2002/08/09 14:15:00   94 (02/08/09 14:15:00) 08/09/02 14:15:00
4 2002/08/08 15:15:00   90 (02/08/08 15:15:00) 08/08/02 15:15:00
5 2002/08/08 16:15:00   88 (02/08/08 16:15:00) 08/08/02 16:15:00
6 2002/08/08 17:15:00   80 (02/08/08 17:15:00) 08/08/02 17:15:00
7 2002/08/08 18:15:00   71 (02/08/08 18:15:00) 08/08/02 18:15:00
8 2002/08/08 19:15:00   76 (02/08/08 19:15:00) 08/08/02 19:15:00
> 
> plot(temp ~ date, data=df)
> plot(temp ~ time, data=df)
> plot(temp ~ datetime, data=df)
> plot(temp ~ dates, data=df)
> plot(temp ~ times, data=df)
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