|  | ## Remove Useless Attributes

#### Synopsis

Remove all useless attributes from an example set.

#### Description

Removes useless attribute from the example set. Useless attributes are

- nominal attributes which most frequent value is contained in more than nominal_useless_above percent of all examples.
- nominal attributes which most frequent value is contained in less than nominal_useless_below percent of all examples.
- numerical attributes which standard deviation is less or equal to a given deviation threshold `t`.

#### Input

- example set input: expects: ExampleSetMetaData: #examples: = 0; #attributes: 0

#### Output

- example set output:
- original:

#### Parameters

- numerical min deviation: Removes all numerical attributes with standard deviation less or equal to this threshold.
- nominal useless above: Removes all nominal attributes which most frequent value is contained in more than this fraction of all examples.
- nominal remove id like: If checked, nominal attributes which values appear only once in the complete exampleset are removed.
- nominal useless below: Removes all nominal attributes which most frequent value is contained in less than this fraction of all examples.

#### ExampleProcess