Learning Tableau 2019 - Third Edition

Lookup and previous value

The first of these two functions gives you the ability to reference values in other rows, while the second gives you the ability to carry forward values. Notice from the following screenshot that direction is very important for these two functions:

Both calculations are computed using an addressing of Category (so Department is the partition).

Here, we've used the code Lookup(ATTR([Category]), -1), which looks up the value of the category in the row offset by -1 from the current one. The first row in each partition gets a NULL result from the lookup (because there isn't a row before it).

For Previous_Value, we used ...