I am working on Mahout and found an issue when I tried to change my csv, previously it was giving me proper recommendations.
Example code:
model = new FileDataModel(new File("E:\\WriteTest.csv"));
UserSimilarity similarity = new PearsonCorrelationSimilarity(model);
UserNeighborhood neighborhood = new NearestNUserNeighborhood(2,similarity,model);
Recommender recomender = new GenericUserBasedRecommender(model,neighborhood, similarity);
List<RecommendedItem> recommendations = recomender.recommend(1,1);
for(RecommendedItem recommendation: recommendations){
System.out.println(recommendation);
}
I have just updated the values of my csv and it has stopped giving me suggestion.
CSV that is not giving me any result:
1,13,9.9
1,26,9.0
1,40,4.0
2,83,9.9
2,167,9.0
2,250,4.0
3,91,9.9
3,167,9.0
3,274,4.0
4,91,9.9
4,167,2.0
CSV which is giving me result:
1,101,5.0
1,102,3.0
1,103,3.0
2,101,5.0
2,102,2.5
2,103,3.0
2,104,2.1
3,101,5.0
3,102,2.5
3,105,4.0
3,107,5.0
4,102,2.0
4,104,4.0
4,105,2.5
4,106,3.0
4,107,2.6
5,101,5.0
5,102,3.4
5,104,2.5
5,105,2.5
5,106,1.0
Output on console respectively:
Result from 1st Dataset Aug 27, 2011 2:45:06 AM org.slf4j.impl.JCLLoggerAdapter info INFO: Creating FileDataModel for file WriteTest.csv Aug 27, 2011 2:45:06 AM org.slf4j.impl.JCLLoggerAdapter info INFO: Reading file info... Aug 27, 2011 2:45:06 AM org.slf4j.impl.JCLLoggerAdapter info INFO: Readlines: 11 Aug 27, 2011 2:45:06 AM org.slf4j.impl.JCLLoggerAdapter info INFO: Processed 4 users
I was expecting Item no 167 but din't find any recommendation
Output of 2nd dataset:
Aug 27, 2011 2:52:42 AM org.slf4j.impl.JCLLoggerAdapter info
INFO: Creating FileDataModel for file WriteTest.csv
Aug 27, 2011 2:52:42 AM org.slf4j.impl.JCLLoggerAdapter info
INFO: Reading file info...
Aug 27, 2011 2:52:42 AM org.slf4j.impl.JCLLoggerAdapter info
INFO: Read lines: 21
Aug 27, 2011 2:52:42 AM org.slf4j.impl.JCLLoggerAdapter info
INFO: Processed 5 users
RecommendedItem[item:105, value:3.25]