Function to standardize time series frequency label

To standardize the frequency description across different sources, this function takes as an input some frequency description, attempts to decipher it, and returns on the following frequencies: c("Annual", "Semiannual", "Quarterly", "Monthly", "Biweekly", "Weekly", "Daily")

standardize_frequency(freq)

Arguments

freq

Character string or vector of strings, each describing the frequency of a time series

Value

Vector of the same length of `freq`, with each value equal to a standard string to describe the frequency. Return value will be one of c("Annual", "Semiannual", "Quarterly", "Monthly", "Biweekly", "Weekly", "Daily")