lag_data: Create a lag

In eeptools: Convenience Functions for Education Data

Create a lag

Description

Lag variables by an arbitrary number of periods even if the data is grouped

Usage

lag_data(df, group, time, periods, values)

Arguments

df	A dataframe with groups, time periods, and a variable to be lagged
group	The grouping factor in the dataframe
time	The variable representing time periods
periods	A scalar for the number of periods to be lagged in the data. Can be negative to indicate leading variable.
values	The names of the variables to be lagged

Value

A dataframe with a newly created variable lagged

Examples

test_data <- expand.grid(id = sample(letters, 10), 
                        time = 1:10)
test_data$value1 <- rnorm(100)
test_data$value2 <- runif(100)
test_data$value3 <- rpois(100, 4)
group <- "id"
time <- "time"
values <- c("value1", "value2")
vars <- c(group, time, values)
periods <- 2
newdat <- lag_data(test_data, group="id", time="time", 
                 values=c("value1", "value2"), periods=3)

eeptools documentation built on June 7, 2023, 5:06 p.m.