Hitachi Vantara Pentaho Community Wiki
Child pages
  • GreedyStepwise
Skip to end of metadata
Go to start of metadata

Package

weka.attributeSelection

Synopsis

GreedyStepwise :

Performs a greedy forward or backward search through the space of attribute subsets. May start with no/all attributes or from an arbitrary point in the space. Stops when the addition/deletion of any remaining attributes results in a decrease in evaluation. Can also produce a ranked list of attributes by traversing the space from one side to the other and recording the order that attributes are selected.

Options

The table below describes the options available for GreedyStepwise.

Option

Description

conservativeForwardSelection

If true (and forward search is selected) then attributes will continue to be added to the best subset as long as merit does not degrade.

generateRanking

Set to true if a ranked list is required.

numToSelect

Specify the number of attributes to retain. The default value (-1) indicates that all attributes are to be retained. Use either this option or a threshold to reduce the attribute set.

searchBackwards

Search backwards rather than forwards.

startSet

Set the start point for the search. This is specified as a comma seperated list off attribute indexes starting at 1. It can include ranges. Eg. 1,2,5-9,17.

threshold

Set threshold by which attributes can be discarded. Default value results in no attributes being discarded. Use in conjunction with generateRanking

  • No labels