\n <\/td>\n | #!/usr/bin/env ruby<\/span><\/td>\n <\/tr>\n \n <\/td>\n | require<\/span> 'mongo-hadoop'<\/span><\/td>\n <\/tr>\n \n <\/td>\n | \n<\/td>\n <\/tr>\n | \n <\/td>\n | MongoHadoop<\/span>.<\/span>reduce<\/span> do<\/span> |key<\/span>,<\/span> values<\/span>|<\/td>\n <\/tr>\n \n <\/td>\n | count<\/span> =<\/span> sum<\/span> =<\/span> 0<\/span><\/td>\n <\/tr>\n \n <\/td>\n | \n<\/td>\n <\/tr>\n | \n <\/td>\n | values<\/span>.<\/span>each<\/span> do<\/span> |value<\/span>|<\/td>\n <\/tr>\n \n <\/td>\n | count<\/span> += 1<\/span><\/td>\n <\/tr>\n \n <\/td>\n | sum<\/span> += value<\/span>[<\/span>'num'<\/span>]<\/span><\/td>\n <\/tr>\n \n <\/td>\n | end<\/span><\/td>\n <\/tr>\n \n <\/td>\n | \n<\/td>\n <\/tr>\n | \n <\/td>\n | {<\/span> :_id<\/span> =><\/span> key<\/span>,<\/span> :average<\/span> =><\/span> sum<\/span> / count<\/span> }<\/span><\/td>\n <\/tr>\n \n <\/td>\n | end<\/span><\/td>\n <\/tr>\n <\/table>\n<\/div>\n\n\n <\/div>\n\n <\/div>\n<\/div>\n\n <\/div>\n | | | | | | | | | |