FastCLARANS.Assignment (ELKI: Environment for DeveLoping KDD-Applications Supported by Index-Structures)

java.lang.Object
- elki.clustering.kmedoids.CLARANS.Assignment
- - elki.clustering.kmedoids.FastCLARANS.Assignment

Enclosing class:: FastCLARANS<V>

protected static class FastCLARANS.Assignment
extends CLARANS.Assignment

Assignment state.

Author:: Erich Schubert

Field Summary

Fields
Modifier and Type Field Description

protected int lastbest
Last best medoid number

(package private) double[] loss
Array for storing the per-medoid loss.
- Fields inherited from class elki.clustering.kmedoids.CLARANS.Assignment
  assignment, distQ, ids, medoids, miter, nearest, second, secondid

Constructor Summary

Constructors
Constructor Description

Assignment(DistanceQuery<?> distQ, DBIDs ids, int k)
Constructor.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`protected double`	`computeCostDifferential(DBIDRef h, double[] pcost)`	Compute the reassignment cost, for one swap.
`protected void`	`computeRemovalCost(double[] pcost)`	Precompute the costs of reassigning to the second closest medoid.
`protected void`	`performLastSwap(DBIDRef h)`	Compute the reassignment cost, for one swap.

Methods inherited from class elki.clustering.kmedoids.CLARANS.Assignment
assignToNearestCluster, computeCostDifferential, recompute

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

- Field Detail
  - loss
```
double[] loss
```
    Array for storing the per-medoid loss.
  - lastbest
```
protected int lastbest
```
    Last best medoid number
- Constructor Detail
  - Assignment
```
public Assignment(DistanceQuery<?> distQ,
                  DBIDs ids,
                  int k)
```
    Constructor.
    
    Parameters:
    
    distQ - Distance query
    
    ids - IDs to process
    
    k - Number of medoids
- Method Detail
  - computeRemovalCost
```
protected void computeRemovalCost(double[] pcost)
```
    Precompute the costs of reassigning to the second closest medoid.
    
    Parameters:
    
    pcost - Output cost
  - computeCostDifferential
```
protected double computeCostDifferential(DBIDRef h,
                                         double[] pcost)
```
    Compute the reassignment cost, for one swap.
    
    Parameters:
    
    h - Current object to swap with any medoid
    
    pcost - Prior cost for removing
    
    Returns:
    
    Cost change
  - performLastSwap
```
protected void performLastSwap(DBIDRef h)
```
    Compute the reassignment cost, for one swap.
    
    Parameters:
    
    h - Current object to swap with the best medoid