scale_yoy: Calculate year-on-year change

In SafeGraphInc/SafeGraphR: Package for Processing and Analyzing SafeGraph Data

Calculate year-on-year change

Description

This takes a data set with a date variable and calculates year-on-year changes for a set of variables of your choice. Returns a data.table.

Usage

scale_yoy(
  data,
  yoy_vars,
  date_var = "date",
  leap_year_fillin = TRUE,
  by = NULL,
  growth = TRUE,
  format_percent = FALSE,
  accuracy = 0.1
)

Arguments

data	Any type of data set that can be coerced to a data.table.
yoy_vars	String vector of the variable names you want to calculate year-on-year change for.
date_var	The name of the date variable, as a string. Must be formatted as Date objects.
leap_year_fillin	If the date is Feb. 29, the previous year will not have a Feb. 29. Set to TRUE to fill in by linear interpolation. If set to TRUE, returned data will be sorted by by and date_var.
by	Character vector of the variable names you'd like the operation to be performed by. There should only be one observation per date per combination of by.
growth	Set to TRUE to get new/old - 1 (i.e. a percentage growth). Set to FALSE to get new/old (i.e. a relative value).
format_percent	Set to TRUE to get back a formatted percentage, i.e. "50%", instead of a number.
accuracy	If format_percent = TRUE, the number of digits after the decimal place to round to, as in scales::percent.

Details

This will add new variables using yoy_vars, adding lag and YOY variants.

Examples

# Create some fake data to do year-on-year calculations with
patterns <- data.table::data.table(date = c(lubridate::ymd('2019-01-15'),
                                lubridate::ymd('2019-01-16'),
                                lubridate::ymd('2020-01-15'),
                                lubridate::ymd('2020-01-16')),
                                visits_by_day = c(1,2,3,4))

# And scale relative to the year before!
scale_yoy(patterns, 'visits_by_day')[]

SafeGraphInc/SafeGraphR documentation built on Nov. 25, 2022, 11:20 a.m.