New default settings for Grid Search

Why did the default settings for Grid Search change?

Answer

In versions prior to 4.5.0.0, the default settings for Grid Search were:

  • Minimum number of observations from a Joinpoint to either end of the data (including the first or last Joinpoint if it falls on an observation): 3
  • Minimum number of observations between two joinpoints (including any joinpoint that falls on an observation): 4
  • Number of points to place between adjacent observed x values in the grid search: 0

 

Starting in version 4.5.0.0, the default settings for Grid Search are now:

  • Min. number of observations from a Joinpoint to either end of the data (excluding first or last joinpoint if it falls on an observation): 2
  • Min. number of observations between two joinpoints (excluding any joinpoint if it falls on an observation): 2
  • Number of points to place between adjacent observed x values in the grid search: 0

 

As you can see, the description for these parameters has changed slightly. These new default settings are identical in results to what you used to get with 3, 4, 0. We made these value and text changes to more accurately describe what was going on in the Grid Search algorithm. For example, if you used to enter 4, 5, 0, then the new values will be 3, 3, 0. If you load an old session with the previous values, they will automatically be updated to the corrected values.

We have also separated these settings from those of Hudson’s Method to make it clear that they function differently for each method.