remove seasonality from weekly time series data
I can't replicate (without having the data), but from what I see, you are trying to apply the decompose function to the entire object - it's probably expecting a single vector, but receives a data-frame-like object and attempts to apply the decomposition to both columns. either use a different time series package (like zoo) which does not store timestamps as a column, or apply decompose explicitly to salestsDec[,2].