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Extract Performance

Synopsis

This operator can be used for deriving a performance measure (in form of a performance vector) from the given ExampleSet.

Description

This operator can be used for generating a performance vector from the properties of the given ExampleSet. This includes properties like the number of examples or number of attributes of the input ExampleSet. Specific data value of the input ExampleSet can also be used as the value of the performance vector. Various statistical properties of the input ExampleSet e.g. average, min or max value of an attribute can also be used as the value of the performance vector. All these options can be understood by studying the parameters and the attached Example Process.

Input

example set

This input port expects an ExampleSet. The performance vector value will be extracted from this ExampleSet.

Output

performance

This port delivers a performance vector. A performance vector is a list of performance criteria values.

example set

The ExampleSet that was given as input is passed without changing to the output through this port. This is usually used to reuse the same ExampleSet in further operators.

Parameters

Performance type

This parameter indicates the way the input ExampleSet should be used to define the performance vector.

  • number_of_examples: If this option is selected, the performance vector value is set to the total number of examples in the input ExampleSet.
  • number_of_attributes: If this option is selected, the performance vector value is set to the total number of attributes in the input ExampleSet.
  • data_value: If this option is selected, the performance vector value is set to the value of the specified attribute at the specified index. The attribute is specified using theattribute nameparameter and the index is specified using theexample indexparameter.
  • statistics: If this option is selected, the performance vector value is set to the value obtained by applying the selected statistical operation on the specified attribute. The attribute is specified using theattribute nameparameter and the statistical operation is selected using thestatisticsparameter.

Statistics

This parameter is only available when theperformance typeparameter is set to 'statistics'. This parameter allows you to select the statistical operation to be applied on the attribute specified by theattribute nameparameter.

Attribute name

This parameter is only available when theperformance typeparameter is set to 'statistics' or 'data value'. This parameter allows you to select the required attribute.

Attribute value

This parameter is only available when theperformance typeparameter is set to 'statistics' and thestatisticsparameter is set to 'count'. This parameter is used for specifying a particular value of the specified attribute. The performance vector value will be set to the number of occurrences of this value in the specified attribute. The attribute is specified by theattribute nameparameter.

Example index

This parameter is only available when theperformance typeparameter is set to 'data value'. This parameter allows you to select the index of the required example of the attribute specified by theattribute nameparameter.

优化方向

This parameter indicates if the performance value should be minimized or maximized.