Automates creating a date since a reference column

Time_Since generates a new dataframe with a column containing time since a reference in a given unit

Usage

Time_Since(df, dcol0, tref, col_name, units = "days")

Arguments

df

a data.table containing the columns of interest

dcol0

list of ending month, day, and year

tref

reference time in date format

col_name

vector of new column names

units

time unit to use

Value

returns the updated dataframe

See also

Other Data Cleaning Functions: Date_Shift(), Event_Count_Gen(), Event_Time_Gen(), Joint_Multiple_Events(), Replace_Missing(), factorize(), gen_time_dep()

Examples

library(data.table)
m0 <- c(1, 1, 2, 2)
m1 <- c(2, 2, 3, 3)
d0 <- c(1, 2, 3, 4)
d1 <- c(6, 7, 8, 9)
y0 <- c(1990, 1991, 1997, 1998)
y1 <- c(2001, 2003, 2005, 2006)
df <- data.table::data.table(
  m0 = m0, m1 = m1,
  d0 = d0, d1 = d1,
  y0 = y0, y1 = y1
)
tref <- strptime("3-22-1997", format = "%m-%d-%Y", tz = "UTC")
df <- Time_Since(df, c("m1", "d1", "y1"), tref, "date_since")