Hi, Should I avoid using 0 as a preference value in mahout’s input file to do recommendation?
I am running mahout-0.9’s recommenditembased on hadoop 2.0 cluster with two nodes, with pearson correlation as similarity class. If I use 1 and 2 as preference values, the generated similarity is correct; but if I use 0 and 1 as preference values, the generated similarity is missing. 1. Input File: 0,0,1 1,0,2 0,1,1 1,1,2 Generated similarity between item 1 and 0 is 0.9999, which is correct 2. Input File: 0,0,0 1,0,1 0,1,0 1,1,1 Similarity is not generated between item 1 and 0, which is not as expected 3. Detailed Command: 1. Run Recommendation mahout recommenditembased -s SIMILARITY_PEARSON_CORRELATION -i 0_1_tuples.csv -o output --numRecommendations 5 --outputPathForSimilarityMatrix similarityMatrix --randomSeed 2014 2. View similarity between item 1 and 0: hdfs dfs -cat similarityMatrix/part-r-00000 Thank you, Peng
