Tableau Calculated Field Help
Tableau newbie here would really appreciate some help with a calculated field.
Let's say I have some data:
| Patient ID | Appointment Date |
|---|---|
| 10001 | 1/1/2019 |
| 10001 | 4/5/2018 |
| 10001 | 2/3/2021 |
| 10002 | 3/2/2019 |
| 10002 | 3/5/2018 |
| 10003 | 1/1/2019 |
| 10003 | 1/3/2021 |
I want to get the previous appointment date in a separate column, based on the sorted ascending appointment date per patient.
I'd like my output to be:
| Patient ID | Appointment Date | Previous Appointment Date |
|---|---|---|
| 10001 | 1/1/2019 | 4/5/2018 |
| 10001 | 4/5/2018 | NULL |
| 10001 | 2/3/2021 | 1/1/2019 |
| 10002 | 3/2/2019 | 3/5/2018 |
| 10002 | 3/5/2018 | NULL |
| 10003 | 1/1/2019 | NUll |
| 10003 | 1/3/2021 | 1/1/2019 |
Eventually, I want to get the average time between each appointment.
I've attempted using LOD functions with window functions, but I can't figure out how to partition based on Patient ID (but I could be doing it wrong). Would anyone have any ideas on how I can achieve the output I want? Thanks in advance!
Topic tableau
Category Data Science