Linear models fail with AttributeError: 'int' object has no attribute 'coef_'

[taynaud]

Hello,

When I try to train a linear model (with SGD, SparkLinearSVC...) I get an exception:

AttributeError: 'int' object has no attribute 'coef_'

Here is a snippet which trigger the error:

from splearn.rdd import DictRDD
from splearn.svm import SparkLinearSVC
from sklearn.datasets import make_classification
import numpy as np

X, y = make_classification(n_classes=2, n_samples=10000, n_features=2, 
                           n_informative=2, n_redundant=0, 
                           n_clusters_per_class=1, random_state=42)

X_rdd = sc.parallelize(X, 4)
y_rdd = sc.parallelize(y, 4)
Z = DictRDD((X_rdd, y_rdd),
            columns=('X', 'y'),
            dtype=[np.ndarray, np.ndarray])

lr = SparkLinearSVC()

lr.fit(Z, classes=np.unique(y))

y_pred_local = local_pipeline.predict(X)
y_pred_dist = dist_pipeline.predict(Z[:, 'X'])

I get

Driver stacktrace:
    at org.apache.spark.scheduler.DAGScheduler.org$apache$spark$scheduler$DAGScheduler$$failJobAndIndependentStages(DAGScheduler.scala:1280)
    at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1268)
    at org.apache.spark.scheduler.DAGScheduler$$anonfun$abortStage$1.apply(DAGScheduler.scala:1267)
    at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59)
    at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:47)
    at org.apache.spark.scheduler.DAGScheduler.abortStage(DAGScheduler.scala:1267)
    at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:697)
    at org.apache.spark.scheduler.DAGScheduler$$anonfun$handleTaskSetFailed$1.apply(DAGScheduler.scala:697)
    at scala.Option.foreach(Option.scala:236)
    at org.apache.spark.scheduler.DAGScheduler.handleTaskSetFailed(DAGScheduler.scala:697)
    at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.doOnReceive(DAGScheduler.scala:1493)
    at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.onReceive(DAGScheduler.scala:1455)
    at org.apache.spark.scheduler.DAGSchedulerEventProcessLoop.onReceive(DAGScheduler.scala:1444)
    at org.apache.spark.util.EventLoop$$anon$1.run(EventLoop.scala:48)
    at org.apache.spark.scheduler.DAGScheduler.runJob(DAGScheduler.scala:567)
    at org.apache.spark.SparkContext.runJob(SparkContext.scala:1813)
    at org.apache.spark.SparkContext.runJob(SparkContext.scala:1826)
    at org.apache.spark.SparkContext.runJob(SparkContext.scala:1839)
    at org.apache.spark.SparkContext.runJob(SparkContext.scala:1910)
    at org.apache.spark.rdd.RDD$$anonfun$collect$1.apply(RDD.scala:905)
    at org.apache.spark.rdd.RDDOperationScope$.withScope(RDDOperationScope.scala:147)
    at org.apache.spark.rdd.RDDOperationScope$.withScope(RDDOperationScope.scala:108)
    at org.apache.spark.rdd.RDD.withScope(RDD.scala:306)
    at org.apache.spark.rdd.RDD.collect(RDD.scala:904)
    at org.apache.spark.api.python.PythonRDD$.collectAndServe(PythonRDD.scala:373)
    at org.apache.spark.api.python.PythonRDD.collectAndServe(PythonRDD.scala)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    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)
Caused by: org.apache.spark.api.python.PythonException: Traceback (most recent call last):
  File "/usr/lib/spark/python/pyspark/worker.py", line 111, in main
    process()
  File "/usr/lib/spark/python/pyspark/worker.py", line 106, in process
    serializer.dump_stream(func(split_index, iterator), outfile)
  File "/usr/lib/spark/python/pyspark/serializers.py", line 263, in dump_stream
    vs = list(itertools.islice(iterator, batch))
  File "/usr/lib/spark/python/pyspark/rdd.py", line 866, in func
    acc = op(obj, acc)
  File "/usr/local/lib/python3.4/dist-packages/splearn/linear_model/base.py", line 27, in __add__
    model.coef_ += other.coef_
AttributeError: 'int' object has no attribute 'coef_'

    at org.apache.spark.api.python.PythonRDD$$anon$1.read(PythonRDD.scala:138)
    at org.apache.spark.api.python.PythonRDD$$anon$1.<init>(PythonRDD.scala:179)
    at org.apache.spark.api.python.PythonRDD.compute(PythonRDD.scala:97)
    at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:297)
    at org.apache.spark.rdd.RDD.iterator(RDD.scala:264)
    at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:66)
    at org.apache.spark.scheduler.Task.run(Task.scala:88)
    at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:214)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    ... 1 more

It is the same with Python 3.4.2 and Python 2.7.9. I use spark 1.5.0

[kszucs]

It has been fixed in 15b6247