====== POM ======

POM stands for Primitives, Operations, Metrics and is a framework built to compute software metrics on PADL models. A paper introducing POM has been published by [[http://www.ptidej.net/publications/Author/ZAIDI-F.php|Zaidi, Guéhéneuc, and Sahraoui]] and can be used as reference. Metrics can be a several kinds:
  * Unary or binary, depending on whether they take as input one or two [[padl|IFirstClassEntity(ies)]];
  * Context dependent or independent, depending on whether they can be computed by considering given [[padl|IFirstClassEntity(ies)]] independently of the rest of the model.

===== Metrics Definition =====

^ Names ^ Definitions ^
| ACAIC	| Ancestor Class-Attribute Import Coupling |
| ACMIC	| Ancestors Class-Method Import Coupling |
| AID	| Average Inheritance Depth of an entity |
| ANA	| Average number of entities from which an entity inherits informations wrt. to the total number of entities in a model |
| CAM	| Relatedness among methods of an entity based on the parameter list of its methods |
| CBO	| Coupling Between Objects of one entity |
| CBOingoing	| Coupling Between Objects of one entity (in-going coupling only, towards the entity) |
| CBOoutgoing	| Coupling Between Objects of one entity (out-going coupling only, from the entity) |
| CIS	| Number of public methods in a class |
| CLD	| Class to Leaf Depth of an entity |
| cohesionAttributes	| Percentage of fields (declared and inherited) used by the declared methods of one entity wrt. all its fields |
| connectivity	| Number of couples of methods that use each other |
| CP	| Number of packages that depend on the package containing the entity |
| DAM	| Ratio of the number of private (and protected) fields wrt. the total number of fields declared in an entity |
| DCAEC	| Descendants Class-Attribute Export Coupling of one entity |
| DCCdesign	| Number of classes that a class is directly related to (by attribute and parameter declarations) |
| DCCimplementation	| Number of classes that a class is directly related to (by attribute declarations and message passing) |
| DCMEC	| Descendants Class-Method Export Coupling of one entity |
| DIT	| Depth of Inheritance Tree of an entity |
| DSC	| Number of top-level entities in a model |
| EIC	| Number of inheritance relationships in which super-entities are in external packages |
| EIP	| Number of inheritance relationships where the super-entity is in the package containing the entity and the sub-entites is in another package |
| FanOut | Number of methods and fields used by one entity |
| ICHClass	| Complexity of an entity as the sum of the complexities of its declared and inherited methods |
| IR | Number of calls from the methods of an entity to the methods and fields declared in its super-entities |
| LCOM1	| Lack of COhesion in Methods of an entity |
| LCOM2	| Lack of COhesion in Methods of an entity |
| LCOM5	| Lack of COhesion in Methods of an entity |
| LOC | Sum of the numbers of lines of code in the methods of an entity |
| McCabe | Sum of the cyclomatic complexities of the operations of an entity |
| MFA	| Ratio of the number of methods inherited by an entity wrt. the number of methods accessible by member methods of the entity |
| MLOCsum | Sum of the numbers of lines of code in the methods of an entity. Same as LOC |
| MOA	| Number of data declarations whose types are user-defined entities |
| NAD	| Number of Attributes Declared by an entity |
| NADextended	| Number of Attributes Declared by an entity and in its member entities |
| NCM	| Number of Changed Methods of an entity wrt. its hierarchy |
| NCP	| Number of Classes Package containing an entity, i.e., the "depth" of the package containment |
| NMA	| Number of Methods Added by an entity wrt. its hierarchy |
| NMD	| Number of Methods Declared by an entity |
| NMDextended	| Number of Methods Declared by an entity and its member entities |
| NMI	| Number of Methods Inherited by an entity. Constructors or not considered as method, they are not counted in the result of the metric |
| NMO	| Number of Methods Overridden by an entity |
| NOA	| Number Of Ancestors of an entity |
| NOC	| Number Of Children of an entity |
| NOD	| Number of descendents of an entity |
| NOF | Number Of Fields declared by an entity |
| NOH	| Number Of Hierarchies in a model |
| NOM	| Number Of Methods declared by an entity |
| NOP	| Number Of Parents of an entity |
| NOParam	| Number of parameters of the methods of an entity |
| NOPM	| Number Of Polymorphic Methods in an entity wrt. its hierarchy |
| NOTC | Number of invocations of JUnit assert methods that occur in the code of a test case |
| NOTI | Number Of Transitive Invocation among methods of a class. See the Law of Demeter for a definition |
| NPrM | Number protected members of an entity |
| oneWayCoupling | Coupling Between Objects of one entity (out-going coupling only, from the entity). Same as CBOoutgoing |
| PIIR	| Number of inheritance relationships existing between entities in the package containing an entity |
| PP	| Number of provider packages of the package containing an entity |
| REIP	| EIP divided by the sum of PIIR and EIP |
| RFC | Response for class: number of methods of an entity and of methods of other entities that are invoked by the methods of the entity |
| RFCextended | Response for class: number of methods of an entity and of methods of other entities that are invoked by the methods of the entity plus number of methods declared by that entity |
| RFP	| Number of references from entities belonging to other packages to entities belonging to the package containing an entity |
| RPII	| PIIR divided by the sum of PIIR and EIP |
| RRFP	| RFP divided by the sum of RFP and the number of internal class references |
| RRTP	| RTP divided by the sum of RTP and the number of internal class references |
| RTP	| Number of references from entities in the package containing an entity to entities in other packages |
| SIX	| Specialisation IndeX of an entity |
| TestCaseLOC | Number of lines of code of all the methods of a test case |
| TLOC | Number of lines of code of all the methods of an entity. Same as LOC |
| VGSum | Sum of the cyclomatic complexities of the operations of an entity. Same as McCabe |
| WMC1	| Weight of an entity considering the complexity of each of its method as being 1. (Default constructors are considered even if not explicitely declared) |
| WMCinvocations	| Weight of an entity considering the complexity of each of its method as being the numbers of invocations that they perform. (Default constructors are considered even if not explicitely declared). |
| WMCmccabe | Weight of an entity considering the complexity of each of its method as being their McCabe cyclomatic complexity. (Default constructors are considered even if not explicitely declared). |

===== Metrics Computation =====

Computing POM metrics using PADL is made easy by the helper class ''pom.helper.MetricsGenerator''. After having installed CPL, PADL, and POM, just go into the ''POM Tests'' project and have a look at this class. It provides a main method with snippets of code to call one of the three methods:
   * ''computeMetricsFromDirectory''
   * ''computeMetricsFromEclipse''
   * ''computeMetricsFromJARs''
which can be used to compute automatically metrics from various input sources. Also have a look at the constant array listing the metrics that must be computed or avoided: ''METRICS_TO_AVOID'' and ''METRICS_TO_COMPUTE''. As other repositories, POM makes it easy [[repositories|to access the different kinds of metrics]].