Coerce time series objects and tibbles with date/date-time columns to ts.
Coerce time series objects and tibbles with date/date-time columns to ts.
tk_zooreg(
data,
select = NULL,
date_var = NULL,
start = 1,
end = numeric(),
frequency = 1,
deltat = 1,
ts.eps = getOption("ts.eps"),
order.by = NULL,
silent = FALSE
)
tk_zooreg_(
data,
select = NULL,
date_var = NULL,
start = 1,
end = numeric(),
frequency = 1,
deltat = 1,
ts.eps = getOption("ts.eps"),
order.by = NULL,
silent = FALSE
)data |
A time-based tibble or time-series object. |
select |
Applicable to tibbles and data frames only.
The column or set of columns to be coerced to |
date_var |
Applicable to tibbles and data frames only.
Column name to be used to |
start |
the time of the first observation. Either a single number or a vector of two integers, which specify a natural time unit and a (1-based) number of samples into the time unit. |
end |
the time of the last observation, specified in the same way
as |
frequency |
the number of observations per unit of time. |
deltat |
the fraction of the sampling period between successive
observations; e.g., 1/12 for monthly data. Only one of
|
ts.eps |
time series comparison tolerance. Frequencies are considered
equal if their absolute difference is less than |
order.by |
a vector by which the observations in |
silent |
Used to toggle printing of messages and warnings. |
tk_zooreg() is a wrapper for zoo::zooreg() that is designed
to coerce tibble objects that have a "time-base" (meaning the values vary with time)
to zooreg class objects. There are two main advantages:
Non-numeric columns get removed instead causing coercion issues.
If an index is present, the returned zooreg object retains an index retrievable using tk_index().
The select argument is used to select subsets
of columns from the incoming data.frame.
The date_var can be used to specify the column with the date index.
If date_var = NULL, the date / date-time column is interpreted.
Optionally, the order.by argument from the underlying xts::xts() function can be used.
The user must pass a vector of dates or date-times if order.by is used.
Only columns containing numeric data are coerced.
At a minimum, a frequency and a start should be specified.
For non-data.frame object classes (e.g. xts, zoo, timeSeries, etc) the objects are coerced
using zoo::zooreg().
tk_zooreg_ is a nonstandard evaluation method.
Returns a zooreg object.
### tibble to zooreg: Comparison between tk_zooreg() and zoo::zooreg()
data_tbl <- tibble::tibble(
date = seq.Date(as.Date("2016-01-01"), by = 1, length.out = 5),
x = rep("chr values", 5),
y = cumsum(1:5),
z = cumsum(11:15) * rnorm(1))
# zoo::zooreg: Values coerced to character; Result does not retain index
data_zooreg <- zoo::zooreg(data_tbl[,-1], start = 2016, freq = 365)
data_zooreg # Numeric values coerced to character
rownames(data_zooreg) # NULL, no dates retained
# tk_zooreg: Only numeric columns get coerced; Result retains index as rownames
data_tk_zooreg <- tk_zooreg(data_tbl, start = 2016, freq = 365)
data_tk_zooreg # No inadvertent coercion to character class
# timetk index
tk_index(data_tk_zooreg, timetk_idx = FALSE) # Regularized index returned
tk_index(data_tk_zooreg, timetk_idx = TRUE) # Original date index returned
### Using select and date_var
tk_zooreg(data_tbl, select = y, date_var = date, start = 2016, freq = 365)
### NSE: Enables programming
select <- "y"
date_var <- "date"
tk_zooreg_(data_tbl, select = select, date_var = date_var, start = 2016, freq = 365)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.