NDCGScorer (Learning to Rank 2.11 API)

java.lang.Object
- ciir.umass.edu.metric.MetricScorer
- - ciir.umass.edu.metric.DCGScorer
  - - ciir.umass.edu.metric.NDCGScorer

public class NDCGScorer
extends DCGScorer

Author:: vdang

Field Summary

Fields
Modifier and Type Field Description

protected java.util.HashMap<java.lang.String,java.lang.Double> idealGains
- Fields inherited from class ciir.umass.edu.metric.DCGScorer
  discount, gain
- Fields inherited from class ciir.umass.edu.metric.MetricScorer
  k

Constructor Summary

Constructors
Constructor Description

NDCGScorer()

NDCGScorer(int k)

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`MetricScorer`	`copy()`
`void`	`loadExternalRelevanceJudgment(java.lang.String qrelFile)`
`java.lang.String`	`name()`
`double`	`score(RankList rl)`	Compute NDCG at k.
`double[][]`	`swapChange(RankList rl)`

Methods inherited from class ciir.umass.edu.metric.DCGScorer
discount, gain, getDCG

Methods inherited from class ciir.umass.edu.metric.MetricScorer
getK, getRelevanceLabels, score, setK

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

- Field Detail
  - idealGains
```
protected java.util.HashMap<java.lang.String,java.lang.Double> idealGains
```
- Constructor Detail
  - NDCGScorer
```
public NDCGScorer()
```
  - NDCGScorer
```
public NDCGScorer(int k)
```
- Method Detail
  - copy
```
public MetricScorer copy()
```
    Overrides:
    
    copy in class DCGScorer
  - loadExternalRelevanceJudgment
```
public void loadExternalRelevanceJudgment(java.lang.String qrelFile)
```
    Overrides:
    
    loadExternalRelevanceJudgment in class MetricScorer
  - score
```
public double score(RankList rl)
```
    Compute NDCG at k. NDCG(k) = DCG(k) / DCG_{perfect}(k). Note that the "perfect ranking" must be computed based on the whole list, not just top-k portion of the list.
    
    Overrides:
    
    score in class DCGScorer
  - swapChange
```
public double[][] swapChange(RankList rl)
```
    Overrides:
    
    swapChange in class DCGScorer
  - name
```
public java.lang.String name()
```
    Overrides:
    
    name in class DCGScorer