a working copy

examples/src/main/python/ml/simple_text_classification_pipeline.py

@@ -21,6 +21,7 @@
 from pyspark.ml.feature import HashingTF, Tokenizer
 from pyspark.ml.classification import LogisticRegression
 
+
 if __name__ == "__main__":
     sc = SparkContext(appName="SimpleTextClassificationPipeline")
     sqlCtx = SQLContext(sc)

python/pyspark/ml/__init__.py

@@ -15,10 +15,10 @@
 # limitations under the License.
 #
 
-from abc import ABCMeta, abstractmethod
+from abc import ABCMeta, abstractmethod, abstractproperty
 
 from pyspark import SparkContext
-from pyspark.sql import inherit_doc # TODO: move inherit_doc to Spark Core
+from pyspark.sql import SchemaRDD, inherit_doc # TODO: move inherit_doc to Spark Core
 from pyspark.ml.param import Param, Params
 from pyspark.ml.util import Identifiable
 
@@ -146,16 +146,17 @@ def getStages(self):
         if self.stages in self.paramMap:
             return self.paramMap[self.stages]
 
-    def fit(self, dataset):
+    def fit(self, dataset, params={}):
+        map = self._merge_params(params)
         transformers = []
         for stage in self.getStages():
             if isinstance(stage, Transformer):
                 transformers.append(stage)
-                dataset = stage.transform(dataset)
+                dataset = stage.transform(dataset, map)
             elif isinstance(stage, Estimator):
-                model = stage.fit(dataset)
+                model = stage.fit(dataset, map)
                 transformers.append(model)
-                dataset = model.transform(dataset)
+                dataset = model.transform(dataset, map)
             else:
                 raise ValueError(
                     "Cannot recognize a pipeline stage of type %s." % type(stage).__name__)
@@ -169,7 +170,65 @@ def __init__(self, transformers):
         super(PipelineModel, self).__init__()
         self.transformers = transformers
 
-    def transform(self, dataset):
+    def transform(self, dataset, params={}):
+        map = self._merge_params(params)
         for t in self.transformers:
-            dataset = t.transform(dataset)
+            dataset = t.transform(dataset, map)
         return dataset
+
+
+@inherit_doc
+class JavaWrapper(object):
+
+    __metaclass__ = ABCMeta
+
+    def __init__(self):
+        super(JavaWrapper, self).__init__()
+
+    @abstractproperty
+    def _java_class(self):
+        raise NotImplementedError
+
+    def _create_java_obj(self):
+        java_obj = _jvm()
+        for name in self._java_class.split("."):
+            java_obj = getattr(java_obj, name)
+        return java_obj()
+
+
+@inherit_doc
+class JavaEstimator(Estimator, JavaWrapper):
+
+    __metaclass__ = ABCMeta
+
+    def __init__(self):
+        super(JavaEstimator, self).__init__()
+
+    @abstractmethod
+    def _create_model(self, java_model):
+        raise NotImplementedError
+
+    def _fit_java(self, dataset, params={}):
+        java_obj = self._create_java_obj()
+        self._transfer_params_to_java(params, java_obj)
+        return java_obj.fit(dataset._jschema_rdd, _jvm().org.apache.spark.ml.param.ParamMap())
+
+    def fit(self, dataset, params={}):
+        java_model = self._fit_java(dataset, params)
+        return self._create_model(java_model)
+
+
+@inherit_doc
+class JavaTransformer(Transformer, JavaWrapper):
+
+    __metaclass__ = ABCMeta
+
+    def __init__(self):
+        super(JavaTransformer, self).__init__()
+
+    def transform(self, dataset, params={}):
+        java_obj = self._create_java_obj()
+        self._transfer_params_to_java(params, java_obj)
+        return SchemaRDD(java_obj.transform(dataset._jschema_rdd,
+                                            _jvm().org.apache.spark.ml.param.ParamMap()),
+                         dataset.sql_ctx)

python/pyspark/ml/classification.py

@@ -16,42 +16,40 @@
 #
 
 from pyspark.sql import SchemaRDD, inherit_doc
-from pyspark.ml import Estimator, Transformer, _jvm
+from pyspark.ml import JavaEstimator, Transformer, _jvm
 from pyspark.ml.param.shared import HasFeaturesCol, HasLabelCol, HasPredictionCol, HasMaxIter,\
     HasRegParam
 
 
 @inherit_doc
-class LogisticRegression(Estimator, HasFeaturesCol, HasLabelCol, HasPredictionCol, HasMaxIter,
+class LogisticRegression(JavaEstimator, HasFeaturesCol, HasLabelCol, HasPredictionCol, HasMaxIter,
                          HasRegParam):
     """
     Logistic regression.
     """
 
-    # _java_class = "org.apache.spark.ml.classification.LogisticRegression"
-
     def __init__(self):
         super(LogisticRegression, self).__init__()
-        self._java_obj = _jvm().org.apache.spark.ml.classification.LogisticRegression()
-
-    def fit(self, dataset, params=None):
-        """
-        Fits a dataset with optional parameters.
-        """
-        java_model = self._java_obj.fit(dataset._jschema_rdd,
-                                        _jvm().org.apache.spark.ml.param.ParamMap())
+
+    @property
+    def _java_class(self):
+        return "org.apache.spark.ml.classification.LogisticRegression"
+
+    def _create_model(self, java_model):
         return LogisticRegressionModel(java_model)
 
 
+@inherit_doc
 class LogisticRegressionModel(Transformer):
     """
     Model fitted by LogisticRegression.
     """
 
-    def __init__(self, _java_model):
-        self._java_model = _java_model
+    def __init__(self, java_model):
+        self._java_model = java_model
 
-    def transform(self, dataset):
+    def transform(self, dataset, params={}):
+        # TODO: handle params here.
         return SchemaRDD(self._java_model.transform(
             dataset._jschema_rdd,
             _jvm().org.apache.spark.ml.param.ParamMap()), dataset.sql_ctx)

python/pyspark/ml/feature.py

@@ -15,91 +15,41 @@
 # limitations under the License.
 #
 
-from pyspark.sql import SchemaRDD, ArrayType, StringType, inherit_doc
-from pyspark.ml import Transformer, _jvm
+from pyspark.sql import inherit_doc
+from pyspark.ml import JavaTransformer
 from pyspark.ml.param import Param
+from pyspark.ml.param.shared import HasInputCol, HasOutputCol
+
 
 @inherit_doc
-class Tokenizer(Transformer):
+class Tokenizer(JavaTransformer, HasInputCol, HasOutputCol):
 
     def __init__(self):
         super(Tokenizer, self).__init__()
-        self.inputCol = Param(self, "inputCol", "input column name", None)
-        self.outputCol = Param(self, "outputCol", "output column name", None)
-        self.paramMap = {}
-
-    def setInputCol(self, value):
-        self.paramMap[self.inputCol] = value
-        return self
-
-    def getInputCol(self):
-        if self.inputCol in self.paramMap:
-            return self.paramMap[self.inputCol]
 
-    def setOutputCol(self, value):
-        self.paramMap[self.outputCol] = value
-        return self
-
-    def getOutputCol(self):
-        if self.outputCol in self.paramMap:
-            return self.paramMap[self.outputCol]
-
-    def transform(self, dataset, params={}):
-        sqlCtx = dataset.sql_ctx
-        if isinstance(params, dict):
-            paramMap = self.paramMap.copy()
-            paramMap.update(params)
-            inputCol = paramMap[self.inputCol]
-            outputCol = paramMap[self.outputCol]
-            # TODO: make names unique
-            sqlCtx.registerFunction("tokenize", lambda text: text.split(),
-                                    ArrayType(StringType(), False))
-            dataset.registerTempTable("dataset")
-            return sqlCtx.sql("SELECT *, tokenize(%s) AS %s FROM dataset" % (inputCol, outputCol))
-        elif isinstance(params, list):
-            return [self.transform(dataset, paramMap) for paramMap in params]
-        else:
-            raise ValueError("The input params must be either a dict or a list.")
+    @property
+    def _java_class(self):
+        return "org.apache.spark.ml.feature.Tokenizer"
 
 
 @inherit_doc
-class HashingTF(Transformer):
+class HashingTF(JavaTransformer, HasInputCol, HasOutputCol):
 
     def __init__(self):
         super(HashingTF, self).__init__()
-        self._java_obj = _jvm().org.apache.spark.ml.feature.HashingTF()
+        #: param for number of features
         self.numFeatures = Param(self, "numFeatures", "number of features", 1 << 18)
-        self.inputCol = Param(self, "inputCol", "input column name")
-        self.outputCol = Param(self, "outputCol", "output column name")
+
+    @property
+    def _java_class(self):
+        return "org.apache.spark.ml.feature.HashingTF"
 
     def setNumFeatures(self, value):
-        self._java_obj.setNumFeatures(value)
+        self.paramMap[self.numFeatures] = value
         return self
 
     def getNumFeatures(self):
-        return self._java_obj.getNumFeatures()
-
-    def setInputCol(self, value):
-        self._java_obj.setInputCol(value)
-        return self
-
-    def getInputCol(self):
-        return self._java_obj.getInputCol()
-
-    def setOutputCol(self, value):
-        self._java_obj.setOutputCol(value)
-        return self
-
-    def getOutputCol(self):
-        return self._java_obj.getOutputCol()
-
-    def transform(self, dataset, paramMap={}):
-        if isinstance(paramMap, dict):
-            javaParamMap = _jvm().org.apache.spark.ml.param.ParamMap()
-            for k, v in paramMap.items():
-                param = self._java_obj.getParam(k.name)
-                javaParamMap.put(param, v)
-            return SchemaRDD(self._java_obj.transform(dataset._jschema_rdd, javaParamMap),
-                             dataset.sql_ctx)
+        if self.numFeatures in self.paramMap:
+            return self.paramMap[self.numFeatures]
         else:
-            raise ValueError("paramMap must be a dict.")
+            return self.numFeatures.defaultValue

python/pyspark/ml/param/__init__.py

@@ -63,3 +63,14 @@ def params(self):
         :py:class:`Param`.
         """
         return filter(lambda x: isinstance(x, Param), map(lambda x: getattr(self, x), dir(self)))
+
+    def _merge_params(self, params):
+        map = self.paramMap.copy()
+        map.update(params)
+        return map
+
+    def _transfer_params_to_java(self, params, java_obj):
+        map = self._merge_params(params)
+        for param in self.params():
+            if param in map:
+                java_obj.set(param.name, map[param])

python/pyspark/ml/param/_gen_shared_params.py

@@ -54,13 +54,13 @@ def set%s(self, value):
         self.paramMap[self.%s] = value
         return self
 
-    def get%s(self, value):
+    def get%s(self):
         if self.%s in self.paramMap:
             return self.paramMap[self.%s]
         else:
-            return self.defaultValue""" % (
+            return self.%s.defaultValue""" % (
         upperCamelName, upperCamelName, doc, name, name, doc, defaultValue, upperCamelName, name,
-        upperCamelName, name, name)
+        upperCamelName, name, name, name)
 
 if __name__ == "__main__":
     print header