LexicalPartitioningStrategy (MG4J (big) 5.4.4)

All Superinterfaces:

PartitioningStrategy, Serializable

All Known Implementing Classes:

ContiguousLexicalStrategy, FrequencyLexicalStrategy
```
public interface LexicalPartitioningStrategy
extends PartitioningStrategy
```
A way to associate a term number with a local index out of a given set and a local term number in the local index.
When partitioning lexically an index (i.e., termwise), we need a way to associate to each term a local index (the index that will contain the postings of that term) and a local term number (the number of the term in the local index).
Usually, a lexical partitioning strategy has a matching LexicalClusteringStrategy whose methods satisfy the following equations:
```
 globalNumber(localIndex(t), localNumber(t)) = t
 <localIndex(globalNumber(i, l)), localNumber(globalNumber(i, l))> = <i, l>
 
```
Author:

Alessandro Arrabito, Sebastiano Vigna

Method Summary

Modifier and Type	Method	Description
`int`	`localIndex(long globalNumber)`	Returns the index to which a given term number is mapped by this strategy.
`long`	`localNumber(long globalNumber)`	Returns the local term number given a global term number.

Methods inherited from interface it.unimi.di.big.mg4j.index.cluster.PartitioningStrategy
numberOfLocalIndices, properties

- Method Detail
  - localIndex
```
int localIndex(long globalNumber)
```
    Returns the index to which a given term number is mapped by this strategy.
    
    Parameters:
    
    globalNumber - the term global number.
    
    Returns:
    
    the corresponding local index, or -1 if the term should be removed from the partitioned index.
  - localNumber
```
long localNumber(long globalNumber)
```
    Returns the local term number given a global term number.
    
    Parameters:
    
    globalNumber - a global term number.
    
    Returns:
    
    the corresponding local term number, or -1 if the term should be removed from the partitioned index.