The following node is available in the Open Source KNIME predictive analytics and data mining platform version 2.7.1. Discover over 1000 other nodes, as well as enterprise functionality at http://knime.com.

Low Variance Filter

Filters out double-compatible columns, whose variance is below a user defined threshold. Columns with low variance are likely to distract certain learning algorithms (in particular those which are distance based) and are therefore better removed.

Note, the input table should not be normalized.

Dialog Options

Column Filter
Variance Upper Bound
Choose a variance value here. The higher the value, the more columns are likely to get filtered out. Choose 0 to filter for columns, which only contain one constant value.
Include
This list contains the column names that are considered for filtering. Any other column will be left untouched (i.e. will also be present in the output table independent of their variance).
Enforce Inclusion
Select this option to enforce the current inclusion list to stay the same even if the input table specification changes. New columns will automatically be added to the exclusion list.
Select
Use these buttons to move columns between the Include and Exclude list.
Search
Use one of these fields to search either within the Include or Exclude list for certain column names or name substrings. Repeated clicking of the search button marks the next column that matches the search text. The check box 'Mark all search hits' causes all matching columns to be selected making them movable between the two lists.
Exclude
This list contains the column names of the input table that will be left untouched (i.e. will also be present in the output table independent of their variance).
Enforce Exclusion
Select this option to enforce the current exclusion list to stay the same even if the input table specification changes. New columns will automatically be added to the inclusion list.

Ports

Input Ports
0 Numeric input data. (Non-numeric columns will be left untouched.)
Output Ports
0 Filtered data.
This node is contained in KNIME Base Nodes provided by KNIME GmbH, Konstanz, Germany.