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Calculate Revisions in Vintage Data

Source: R/revisions.R
get_revisions.Rd

Computes revisions in vintage data based on specified reference points: a fixed reference date, the nth release, or a specified interval. This function allows users to analyze differences between data vintages across time.

Usage

get_revisions(df, interval = NULL, nth_release = NULL, ref_date = NULL)

Arguments

df

A data frame containing vintage data. The data frame must include at least the following columns:

  • pub_date: The publication date of each vintage.

  • time: The reference period (e.g., quarter or month).

  • value: The observed value for the given vintage and reference period.

interval

A positive integer specifying the lag (in periods) between vintages to compute revisions. Defaults to 1 if no other parameter is specified.

nth_release

A positive integer or "latest", specifying the release to use as a reference for revisions. If "latest", the most recent vintage is used.

ref_date

A date specifying the fixed reference publication date to compare all vintages against.

Value

A data frame (tibble) of class tbl_revision, with the following columns:

  • pub_date: The publication date of the vintage.

  • time: The reference period (e.g., quarter or month).

  • value: The calculated revision, i.e., the difference between the observed value and the reference value.

Details

The function supports three mutually exclusive methods for calculating revisions:

  • Reference date (ref_date): Computes revisions relative to a fixed publication date.

  • Interval (interval): Computes revisions relative to vintages published interval periods earlier.

  • Nth release (nth_release): Computes revisions relative to the nth vintage release for each reference period.

If no method is explicitly specified, interval = 1 is used by default.

Input validation ensures that only one of ref_date, nth_release, or interval is specified.

Examples

# Example data
df <- dplyr::filter(reviser::gdp , id=="US")

# Calculate revisions using an interval of 1
revisions_interval <- get_revisions(df, interval = 1)

# Calculate revisions using a fixed reference date
revisions_date <- get_revisions(df, ref_date = as.Date("2023-02-01"))

# Calculate revisions relative to the nth release (2nd release)
revisions_nth <- get_revisions(df, nth_release = 1)