Apache spark MLlib MatrixFactoryModel recommendProducts(用户,num)在某些用户上失败
我培训了一个使用和现在使用的模型,以获得最佳推荐产品,但代码在某些用户身上失败,出现以下错误:Apache spark MLlib MatrixFactoryModel recommendProducts(用户,num)在某些用户上失败,apache-spark,apache-spark-mllib,collaborative-filtering,matrix-factorization,Apache Spark,Apache Spark Mllib,Collaborative Filtering,Matrix Factorization,我培训了一个使用和现在使用的模型,以获得最佳推荐产品,但代码在某些用户身上失败,出现以下错误: user_products = model.call("recommendProducts", user, prodNum) File "/usr/lib/spark/python/pyspark/mllib/common.py", line 136, in call return callJavaFunc(self._sc, getattr(self._java_model, nam
user_products = model.call("recommendProducts", user, prodNum)
File "/usr/lib/spark/python/pyspark/mllib/common.py", line 136, in call
return callJavaFunc(self._sc, getattr(self._java_model, name), *a)
File "/usr/lib/spark/python/pyspark/mllib/common.py", line 113, in callJavaFunc
return _java2py(sc, func(*args))
File "/usr/lib/spark/python/lib/py4j-0.8.2.1-src.zip/py4j/java_gateway.py", line 538, in __call__
File "/usr/lib/spark/python/lib/py4j-0.8.2.1-src.zip/py4j/protocol.py", line 300, in get_return_value
py4j.protocol.Py4JJavaError: An error occurred while calling o68.recommendProducts.
: java.util.NoSuchElementException: next on empty iterator
at scala.collection.Iterator$$anon$2.next(Iterator.scala:39)
at scala.collection.Iterator$$anon$2.next(Iterator.scala:37)
at scala.collection.IndexedSeqLike$Elements.next(IndexedSeqLike.scala:64)
at scala.collection.IterableLike$class.head(IterableLike.scala:91)
at scala.collection.mutable.WrappedArray.scala$collection$IndexedSeqOptimized$$super$head(WrappedArray.scala:34)
at scala.collection.IndexedSeqOptimized$class.head(IndexedSeqOptimized.scala:120)
at scala.collection.mutable.WrappedArray.head(WrappedArray.scala:34)
at org.apache.spark.mllib.recommendation.MatrixFactorizationModel.recommendProducts(MatrixFactorizationModel.scala:117)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:231)
at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:379)
at py4j.Gateway.invoke(Gateway.java:259)
at py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:133)
at py4j.commands.CallCommand.execute(CallCommand.java:79)
at py4j.GatewayConnection.run(GatewayConnection.java:207)
at java.lang.Thread.run(Thread.java:745)
正如你们在上面第一行看到的,我正在跑步
user_products = model.call("recommendProducts", user, prodNum)
而不是
user_products = model.recommendProducts(user, prodNum)
因为我使用的1.3.0 pyspark没有实现后者。
无论如何,它正确地为某些用户返回预测,但在其他用户上则失败
我知道它可能没有我要求的准确预测数,我希望它返回的预测数会更少。简短回答:
- 您已经就用户ID在[0;N]范围内的评分对模型进行了培训
- 您要求推荐userID=N+x,其中x是正整数。这导致了异常
- 您可以在培训阶段使用的用户ID空间内征求建议
- 您可以根据培训阶段使用的产品空间要求尽可能多的建议
(如果我遗漏了什么,请在下面的评论中更正)是。这是正确的。我之前就知道了,但忘了更新