From the Settings > Manage Data tab, click to Edit an existing table. Click the Add Derived Column button in the lower-left corner.
In the Edit Derived Column dialog, type a D programming language function that returns a long datatype, then click Save Derived Column. See Derived column syntax for details.
Now you can refer to your derived column normally in the user interface. In this example, we are grouping by the new
funding_round_size derived column which allows us to quickly see the number of funding events that fall into four size buckets (<1M, 1-10M, 10-100M and >100M).
See Derived column examples for detailed examples about building and using derived columns.