Package com.tngtech.archunit.library.metrics

Class LakosMetrics

java.lang.Object

com.tngtech.archunit.library.metrics.LakosMetrics

@PublicAPI(usage=ACCESS)
public final class LakosMetrics
extends Object

Calculates architecture metrics as defined by John Lakos in his book "Large-Scale C++ Software Design".
To calculate these metrics every component is assigned a "dependsOn" value that represents the number of other components that this component can reach transitively, including itself. Take e.g. components

 A -> B -> C
 A -> D
 

Then dependsOn(A) = 4, dependsOn(B) = 2, dependsOn(C) = 1, dependsOn(D) = 1
The Lakos metrics are then calculated as:

• Cumulative Component Dependency (CCD): The sum of all dependsOn values of all components
• Average Component Dependency (ACD): The CCD divided by the number of all components
• Relative Average Component Dependency (RACD): The ACD divided by the number of all components
• Normalized Cumulative Component Dependency (NCCD): The CCD of the system divided by the CCD of a balanced binary tree with the same number of components

Given the example graph above we would obtain CCD = 4 + 2 + 1 + 1 = 8, ACD = 8 / 4 = 2, RACD = 2 / 4 = 0.5, NCCD = 8 / 8 = 1.0

Method Summary

Modifier and Type	Method	Description
double	getAverageComponentDependency()	The Average Component Dependency (ACD) of the components.
int	getCumulativeComponentDependency()	The Cumulative Component Dependency (CCD) of the components.
double	getNormalizedCumulativeComponentDependency()	The Normalized Cumulative Component Dependency (NCCD) of the components.
double	getRelativeAverageComponentDependency()	The Relative Average Component Dependency (RACD) of the components.
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Method Details

getCumulativeComponentDependency

@PublicAPI(usage=ACCESS)
public int getCumulativeComponentDependency()

The Cumulative Component Dependency (CCD) of the components.

See Also:

• LakosMetrics

getAverageComponentDependency

@PublicAPI(usage=ACCESS)
public double getAverageComponentDependency()

The Average Component Dependency (ACD) of the components.

See Also:

• LakosMetrics

getRelativeAverageComponentDependency

@PublicAPI(usage=ACCESS)
public double getRelativeAverageComponentDependency()

The Relative Average Component Dependency (RACD) of the components.

See Also:

• LakosMetrics

getNormalizedCumulativeComponentDependency

@PublicAPI(usage=ACCESS)
public double getNormalizedCumulativeComponentDependency()

The Normalized Cumulative Component Dependency (NCCD) of the components.

See Also:

• LakosMetrics

toString

public String toString()

Overrides:

toString in class Object