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_single(freq)

Arguments

freq

Character string, describing the frequency of a time series

Value

Standardized character string to describe the frequency, one of c("Annual", "Semiannual", "Quarterly", "Monthly", "Biweekly", "Weekly", "Daily")