Convert from annual to quarterly data, constrained to annual average
问题 I have several variables at annual frequency in R that I would like to include in a regression analysis with other variables available at quarterly frequency. Additionally, I would like to be able to convert the quarterly data back to annual frequency in a way that reproduces the original annual data. My current approach when converting from low frequency to high frequency time series data is to use the na.spline function in the zoo package. However, I don’t see how to constrain the quarterly