[[Property:title|Defining derived metrics]]
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To define a derived metric, you must select the''' Metric Definition''' tab and click the '''New metric''' button. A menu appears asking you the kind of metric you want to define. Select '''Basic metric''' and then the type of the results you are looking for (i.e. Class, Feature, Line, ...). Once done, you can perform the following steps:
# Enter a name for the metric in the "Name" field. Next to the field you will see the type of metric as well as the unit for this metric.
# Enter a description for the metric. The description is shown as a tooltip when you navigate the list of available metrics.
#  Choose your criteria by selecting the item with ... in the '''Criterion definition''' list. Once selected you can press Ctrl+Space to see the list of available criterion. Once the criterion is set, you can add some properties (e.g. a property could be <eiffel>STRING</eiffel> if the criterion you have is to look for descendants of the <eiffel>STRING</eiffel> class). 
# Once you have completed the metric definition you need to save your metric by clicking on the Save button.
# If you want to define another derived metric, repeat all the previous steps.

For more information about criterion, read the [[Criterion References|Managing criterion]]  section.

A summary of the metric you just defined appears in a textual representation in the '''Expression''' text field.

{{seealso|<br/>
[[Managing new metrics|Managing metrics]]  <br/>
[[Criterion References|Managing criterion]]  }}