CycleExistenceAnalysis

java.lang.Object
- ptolemy.graph.analysis.Analysis
- - ptolemy.graph.analysis.CycleExistenceAnalysis

```
public class CycleExistenceAnalysis
extends Analysis
```
Analyzes a directed graph and detects the existence of cycles. In other words, this analysis checks if a given directed graph has at least one cycle or not. The default analyzer runs in O(N^3) in which N is the number of nodes.

Since:

Ptolemy II 4.0

Version:

$Id$

Author:

Shahrooz Shahparnia

Pt.AcceptedRating:

Red (ssb)

Pt.ProposedRating:

Red (shahrooz)

Constructor Summary

Constructors
Constructor	Description
`CycleExistenceAnalysis(CycleExistenceAnalyzer analyzer)`	Construct an instance of this class with a given analyzer.
`CycleExistenceAnalysis(Graph graph)`	Construct an instance of this class for a given graph, using a default analyzer that runs in O(N^3) in which N is the number of nodes.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`boolean`	`hasCycle()`	Check if the graph under analysis has at least one cycle.
`java.lang.String`	`toString()`	Return a description of the analysis and the associated analyzer.
`boolean`	`validAnalyzerInterface(Analyzer analyzer)`	Check if a given analyzer is compatible with this analysis.

Methods inherited from class ptolemy.graph.analysis.Analysis
analyzer, changeAnalyzer, graph, valid

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - CycleExistenceAnalysis
```
public CycleExistenceAnalysis(Graph graph)
```
    Construct an instance of this class for a given graph, using a default analyzer that runs in O(N^3) in which N is the number of nodes.
    
    Parameters:
    
    graph - The given directed graph.
  - CycleExistenceAnalysis
```
public CycleExistenceAnalysis(CycleExistenceAnalyzer analyzer)
```
    Construct an instance of this class with a given analyzer.
    
    Parameters:
    
    analyzer - The default Analyzer.
- Method Detail
  - hasCycle
```
public boolean hasCycle()
```
    Check if the graph under analysis has at least one cycle.
    
    Returns:
    
    True if the graph under analysis has at least one cycle.
  - toString
```
public java.lang.String toString()
```
    Return a description of the analysis and the associated analyzer.
    
    Overrides:
    
    toString in class Analysis
    
    Returns:
    
    A description of the analysis and the associated analyzer.
  - validAnalyzerInterface
```
public boolean validAnalyzerInterface(Analyzer analyzer)
```
    Check if a given analyzer is compatible with this analysis. In other words if it is possible to use it to compute the computation associated with this analysis.
    
    Overrides:
    
    validAnalyzerInterface in class Analysis
    
    Parameters:
    
    analyzer - The given analyzer.
    
    Returns:
    
    True if the given analyzer is valid for this analysis.