title: Ranking Dates Based on Another Column - Spotfire
body: <p>Does anyone know of way to circumvent the Spotfire limitation for using the OVER function to RANK or order dates when using a custom expression? </p>
  
  <p>Providing a little background, I am trying to identify or mark a lease based on the below data as 1, 2, 3 etc. For example, since we see twice 63 in the left column, I would like to return a 1 and a 2 to identify the two different leases, starting on 1/1/2016 and 8/1/2016. Then a 1 and 2 for 72, a 1 for 140 and so one. Unfortunately, OVER functions can only be used with aggregation methods and I don't know of another method to produce the result that I am looking for.</p>
  
  <pre><code>Tenant Lease_From  Lease_To     Tenant_status
  63     1/1/2016    1/31/2017    Current
  63     8/1/2017    7/31/2018    Current
  72     10/1/2016   7/31/2017    Current
  72     8/1/2017    7/31/2018    Current
  140    2/1/2017    7/31/2018    Current
  149    8/1/2016    7/31/2017    Current
  149    8/1/2017    7/31/2018    Current
  156    1/15/2017   3/31/2018    Current
  156    4/1/2018    3/31/2019    Current
  </code></pre>