我按照website中的指南进行操作，选择“样本笔记本”-深度学习图像分类（look here），当我运行ml = MLContext(sc)时，发生如下错误：
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
~/.local/lib/python3.5/site-packages/systemml/classloader.py in createJavaObject(sc, obj_type)
86 try:
---> 87 return _createJavaObject(sc, obj_type)
88 except (py4j.protocol.Py4JError, TypeError):
~/.local/lib/python3.5/site-packages/systemml/classloader.py in _createJavaObject(sc, obj_type)
46 if obj_type == 'mlcontext':
---> 47 return sc._jvm.org.apache.sysml.api.mlcontext.MLContext(sc._jsc)
48 elif obj_type == 'dummy':
TypeError: 'JavaPackage' object is not callable
During handling of the above exception, another exception occurred:
Py4JJavaError Traceback (most recent call last)
<ipython-input-5-724894051c3e> in <module>()
----> 1 ml = MLContext(sc)
~/.local/lib/python3.5/site-packages/systemml/mlcontext.py in __init__(self, sc)
697 raise ValueError("Expected sc to be a SparkContext or SparkSession, got " % str(type(sc)))
698 self._sc = sc
--> 699 self._ml = createJavaObject(sc, 'mlcontext')
700
701 def __repr__(self):
~/.local/lib/python3.5/site-packages/systemml/classloader.py in createJavaObject(sc, obj_type)
92 # First load SystemML
93 jar_file_name = _getJarFileName(sc, '')
---> 94 x = _getLoaderInstance(sc, jar_file_name, 'org.apache.sysml.utils.SystemMLLoaderUtils', hint + 'SystemML.jar')
95 x.loadSystemML(jar_file_name)
96 try:
~/.local/lib/python3.5/site-packages/systemml/classloader.py in _getLoaderInstance(sc, jar_file_name, className, hint)
69 jar_file_url_arr[0] = jar_file_url
70 url_class_loader = sc._jvm.java.net.URLClassLoader(jar_file_url_arr, sc._jsc.getClass().getClassLoader())
---> 71 c1 = sc._jvm.java.lang.Class.forName(className, True, url_class_loader)
72 return c1.newInstance()
73 else:
/usr/local/lib/python3.5/dist-packages/py4j/java_gateway.py in __call__(self, *args)
1158 answer = self.gateway_client.send_command(command)
1159 return_value = get_return_value(
-> 1160 answer, self.gateway_client, self.target_id, self.name)
1161
1162 for temp_arg in temp_args:
~/software/spark-2.1.0-bin-hadoop2.7/python/pyspark/sql/utils.py in deco(*a, **kw)
61 def deco(*a, **kw):
62 try:
---> 63 return f(*a, **kw)
64 except py4j.protocol.Py4JJavaError as e:
65 s = e.java_exception.toString()
/usr/local/lib/python3.5/dist-packages/py4j/protocol.py in get_return_value(answer, gateway_client, target_id, name)
318 raise Py4JJavaError(
319 "An error occurred while calling {0}{1}{2}.\n".
--> 320 format(target_id, ".", name), value)
321 else:
322 raise Py4JError(
Py4JJavaError: An error occurred while calling z:java.lang.Class.forName.
: java.lang.ClassNotFoundException: org.apache.sysml.utils.SystemMLLoaderUtils
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:348)
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:498)
at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:244)
at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:357)
at py4j.Gateway.invoke(Gateway.java:280)
at py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:132)
at py4j.commands.CallCommand.execute(CallCommand.java:79)
at py4j.GatewayConnection.run(GatewayConnection.java:214)
at java.lang.Thread.run(Thread.java:748)
似乎找不到SystemML.jar？我下载的systemml二进制文件可能包含此文件。但是我不知道该怎么办。
谢谢！谢谢！！！
最佳答案
如您正确指出的那样，发生错误是因为找不到SystemML类。有两种方法可以解决此问题：
（推荐）而不是下载python文件，我建议通过pip安装SystemML：pip install systemml（发行版）或pip install https://sparktc.ibmcloud.com/repo/latest/systemml-1.0.0-SNAPSHOT-python.tar.gz（最新代码）。这样可以包装必要的罐子。
如果您更喜欢使用下载的python文件，则必须通过pyspark的--driver-class-path选项提供SystemML.jar和systemml-*-extra.jar。