Examples Page for the Matching and Mahalanobis Distance Matrix Web Apps

2008-03-10

• exPTSD01.csv
  • This creates a singular matrix by including dummy variables for 7 of 7 sites.
  • The resulting output, exPTSD01-results.htm, fails rather nicely.
• exPTSD02.csv
  • This corrects the singularity in exPTSD01 by dropping the column for site 1.
  • The resulting output, exPTSD02-distances.csv, looks good.
  • (Possible Bug) However, this distance matrix does not return results when input to the Matching app.
    • Tried dropping the id column, but that didn't fix it.
    • Ah, we've exceeded the digit length at least for this 24x24 matrix. It looks like the matching app will take 8 digits max. We use 9 for the regular distances and 10 for the diagonal or max dist. It looks like we should use 99,999,999 for the max dist. It doesn't matter what the diagonal is set to; 0 or 99,999,999 or 2,000,000,000 all work fine.
    • The matching app does not fail as nicely as the Mahalanobis app. The matching app returns a blank screen. The Mahalanobis app returns the error message.
  • FIXED
    • Mahalnobis now shifts distances to have a maximum of 8 digits - the new max is 200,000,000.
    • Matching now displays nice warnings - in the case of distances greater than 8 digits, it shifts values as necessary and displays a warning

2008-05-19

• morematch
• exPTSD03.csv