This vignette introduces the DTSg
package, shows how to create objects of its main class and explains their two interfaces: R6 and S3. Familiarity with the data.table
package helps better understanding certain parts of the vignette, but is not essential to follow it.
First, let’s load some data. The package is shipped with a data.table
containing a daily time series of river flow:
library(data.table)
library(DTSg)
data(flow)
flow
#> date flow
#> 1: 2007-01-01 9.540
#> 2: 2007-01-02 9.285
#> 3: 2007-01-03 8.940
#> 4: 2007-01-04 8.745
#> 5: 2007-01-05 8.490
#> ---
#> 2165: 2012-12-27 26.685
#> 2166: 2012-12-28 28.050
#> 2167: 2012-12-29 23.580
#> 2168: 2012-12-30 18.840
#> 2169: 2012-12-31 17.250
summary(flow)
#> date flow
#> Min. :2007-01-01 00:00:00 Min. : 4.995
#> 1st Qu.:2008-07-19 00:00:00 1st Qu.: 8.085
#> Median :2010-01-12 00:00:00 Median : 11.325
#> Mean :2010-01-08 23:32:46 Mean : 16.197
#> 3rd Qu.:2011-07-08 00:00:00 3rd Qu.: 18.375
#> Max. :2012-12-31 00:00:00 Max. :290.715
Now that we have a data set, we can create our first object by providing it to the new
method of the package’s main class generator DTSg
. In addition, we specify an ID in order to give the new object a name:
TS <- DTSg$new(values = flow, ID = "River Flow")
Creating an object with the package’s alternative interface abusing an S4 constructor looks like this:
TS <- new(Class = "DTSg", values = flow, ID = "River Flow")
Printing the object shows us the data provided, the specified ID, some more slots for metadata, which we left empty, as well as that the object represents a regular UTC time series with a periodicity of one day. It also shows us that the first column has been renamed to .dateTime. This columns serves as its time index and cannot be changed at will:
TS$print() # or print(TS) or just TS
#> Values:
#> .dateTime flow
#> <POSc> <num>
#> 1: 2007-01-01 9.540
#> 2: 2007-01-02 9.285
#> 3: 2007-01-03 8.940
#> 4: 2007-01-04 8.745
#> 5: 2007-01-05 8.490
#> ---
#> 2188: 2012-12-27 26.685
#> 2189: 2012-12-28 28.050
#> 2190: 2012-12-29 23.580
#> 2191: 2012-12-30 18.840
#> 2192: 2012-12-31 17.250
#>
#> ID: River Flow
#> Parameter:
#> Variant:
#> Unit:
#> Aggregated: FALSE
#> Regular: TRUE
#> Periodicity: Time difference of 1 days
#> Time zone: UTC
With this done, we can move on and further explore our time series with a summary (summary
), a report on missing values (nas
) and a plot (plot
). It suddenly seems to contain several missing values which apparently were not there upon loading the data set (plot
requires the xts
, dygraphs
and RColorBrewer
packages to be installed; HTML vignettes unfortunately cannot display interactive elements, hence I included a static image of the JavaScript chart instead):
TS$summary() # or summary(TS)
#> flow
#> Min. : 4.995
#> 1st Qu.: 8.085
#> Median : 11.325
#> Mean : 16.197
#> 3rd Qu.: 18.375
#> Max. :290.715
#> NA's :23
TS$nas(cols = "flow") # or nas(TS, cols = "flow")
#> .col .group .from .to .n
#> 1: flow 1 2007-10-12 2007-10-24 13
#> 2: flow 2 2007-10-26 2007-11-03 9
#> 3: flow 3 2007-11-10 2007-11-10 1
if (requireNamespace("xts", quietly = TRUE) &&
requireNamespace("dygraphs", quietly = TRUE) &&
requireNamespace("RColorBrewer", quietly = TRUE)) {
TS$plot(cols = "flow") # or plot(TS, cols = "flow")
}