QMatrix (ELKI: Environment for DeveLoping KDD-Applications Supported by Index-Structures)

All Known Implementing Classes:

CachedQMatrix, Kernel, R2_Qq, SVC_Q, SVR_Q
```
public interface QMatrix
```
API to get kernel similarity values.

Since:

0.8.0

Author:

Erich Schubert

Method Summary

All Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method	Description
`default void`	`get_Q(int column, int len, float[] out)`	Get a column of the matrix.
`double[]`	`get_QD()`	Get the diagonal values, as reference.
`void`	`initialize()`	Initialize the Q Matrix.
`double`	`similarity(int i, int j)`	(Slow) compute the similarity (not distance) of objects i and j.
`void`	`swap_index(int i, int j)`	Reorganize the data by swapping two entries.

- Method Detail
  - get_Q
```
default void get_Q(int column,
                   int len,
                   float[] out)
```
    Get a column of the matrix.
    
    Parameters:
    
    column - Column number
    
    len - Number of entries to get
    
    out - Output array for similarity values
  - get_QD
```
double[] get_QD()
```
    Get the diagonal values, as reference.
    
    Returns:
    
    Diagonal values
  - swap_index
```
void swap_index(int i,
                int j)
```
    Reorganize the data by swapping two entries.
    This also must modify the QD array!
    
    Parameters:
    
    i - First entry
    
    j - Second entry
  - similarity
```
double similarity(int i,
                  int j)
```
    (Slow) compute the similarity (not distance) of objects i and j.
    If you need many, use get_Q(int, int, float[]) instead.
    
    Parameters:
    
    i - First object
    
    j - Second object
    
    Returns:
    
    Similarity
  - initialize
```
void initialize()
```
    Initialize the Q Matrix.