Amitai questions

• Seasonality in auto.arima() from forecast package
• How to get indices of top k values for each (selected) column in data.table
• R How to convert a numeric into factor with predefined labels
• How to efficiently split a big data.table into two according to a rule that involves 2 columns?
• Transpose a data.table (columns names -> first column of output)
• Data.Table rolling join by group

Amitai answers