R: Create a 'List-Date' Frequency

f.list.date

R Documentation

Create a `List-Date` Frequency

Description

Use this frequency for data with date labels. It is generally a list of dates, but it can also be used to label observations outside this list.

Usage

f.list.date(items, value = NULL, reformat = TRUE)

Arguments

`items`	The items in the list in `YYYYMMDD` format.
`value`	The current value in `YYYYMMDD` format. If null, the first value in `items` is used.
`reformat`	If the elements of `items` are not in `YYYYMMDD` format, set this to be `TRUE`.

Details

In order to use the as.frequency function for this type of frequency, you need the following information:

Character Format: "YYYYMMDD" (i.e., the item)
Class Id: Ld or Ld:... (where '...' represents the semi-colon-separated items)

Value

An object of class ldtf. It is also a list with the following members:

`class`	Determines the class of this frequency.
`items`	Determines the `items`.
`value`	Determines the `value`.

Examples


Ld0 <- f.list.date(c("20231101","20220903","20200823","20230303"), "20200823")

Ld0_value_str <-  as.character(Ld0) # this will be '20200823'.
Ld0_class_str <- get.class.id(Ld0)
#      this will be 'Ld:20231101;20220903;20200823;20230303'.

Ld_new <- as.frequency("20231101", "Ld:20231101;20220903;20200823;20230303")
Ld_new0 <- as.frequency("20231101", "Ld")
#     compared to the previous one, its items will be empty

# Don't make the following mistakes:

Ld_invalid <- try(as.frequency("20231102", "Ld:20231101;20220903;20200823;20230303"))
  # 'E' is not a member of the list
Ld_invalid <- try(f.list.date(c("20231101","20220903","20200823","20230303"), "20231102"))