[R] Change data frame to time series data

[roslinazairimah zakaria]

Hi Enrico, yes it works. I can also plot the graph.
Next question, how do I delete the date from 16 December until 31 December
2014?


Thank you very much.

> dt$time <- as.POSIXct(dt$time)> > dt_ts <- xts(dt$count, dt$time)> str(dt_ts)An xts object on 2014-01-01 / 2014-12-31 23:59:00 containing:
  Data:    integer [525600, 1]
  Index:   POSIXct,POSIXt [525600] (TZ: "")


plot(dt_ts)


On Wed, Oct 2, 2024 at 3:01 PM Enrico Schumann <es using enricoschumann.net>
wrote:

> On Wed, 02 Oct 2024, roslinazairimah zakaria writes:
>
> > Dear all, I have a data in data frame and would like to change to time
> > series data. Thank you for any help given.
> >
> >> str(dt)'data.frame': 525600 obs. of  3 variables:
> >  $ time             : chr  "2014-01-01 00:00:00" "2014-01-01 00:01:00"
> > "2014-01-01 00:02:00" "2014-01-01 00:03:00" ...
> >  $ cnt_charge_events: int  0 0 0 0 0 0 0 0 0 0 ...
> >  $ count            : int  0 0 0 0 0 0 0 0 0 0 ...
> >
> >> head(dt)                 time cnt_charge_events count
> > 1 2014-01-01 00:00:00                 0     0
> > 2 2014-01-01 00:01:00                 0     0
> > 3 2014-01-01 00:02:00                 0     0
> > 4 2014-01-01 00:03:00                 0     0
> > 5 2014-01-01 00:04:00                 0     0
> > 6 2014-01-01 00:05:00                 0     0
> >
> >
> >> dt_ts <- xts(dt$count, dt$time)Error in xts(dt$count, dt$time) :
> >   order.by requires an appropriate time-based object> head(dt_ts)Time
> Series:
> > Start = 1
> > End = 6
> > Frequency = 1
> >   dt_ts.date dt_ts.time dt[, 3]
> > 1      16071          1       0
> > 2      16071          2       0
> > 3      16071          3       0
> > 4      16071          4       0
> > 5      16071          5       0
> > 6      16071          6       0Dear
>
>
> Your "time" column consists of character strings, not
> actual timestamps.
>
>   dt <- read.table(
>   text ="
>   time, cnt_charge_events, count
>   2014-01-01 00:00:00, 1, 1
>   2014-01-01 00:01:00, 2, 2
>   2014-01-01 00:02:00, 3, 3
>   2014-01-01 00:03:00, 4, 4
>   2014-01-01 00:04:00, 5, 5
>   2014-01-01 00:05:00, 6, 6",
>   header = TRUE, sep = ",")
>
>   library("xts")
>   xts(dt$count, dt$time)  ## won't work
>   ## Error in xts(dt$count, dt$time) :
>   ##   order.by requires an appropriate time-based object
>
>   dt$time <- as.POSIXct(dt$time)
>   xts(dt$count, dt$time)
>   ##                     [,1]
>   ## 2014-01-01 00:00:00    1
>   ## 2014-01-01 00:01:00    2
>   ## 2014-01-01 00:02:00    3
>
> But be sure to read about ?as.POSIXct; in particular,
> the handling of timezones/daylight-saving time.
>
>
> > [[alternative HTML version deleted]]
>
> Please send plain-text messages to this list; otherwise,
> the results become hard to read.
>
> --
> Enrico Schumann
> Lucerne, Switzerland
> https://enricoschumann.net
>


-- 
*Roslinazairimah Zakaria*
*Tel: +609-5492370; Fax. No.+609-5492766*

*Email: roslinazairimah using ump.edu.my <roslinazairimah using ump.edu.my>;
roslinaump using gmail.com <roslinaump using gmail.com>*
Faculty of Industrial Sciences & Technology
University Malaysia Pahang
Lebuhraya Tun Razak, 26300 Gambang, Pahang, Malaysia

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