gen numFeatures

Author: mengxr

python/pyspark/ml/feature.py

@@ -17,8 +17,7 @@
 
 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
+from pyspark.ml.param.shared import HasInputCol, HasOutputCol, HasNumFeatures
 
 
 @inherit_doc
@@ -33,23 +32,11 @@ def _java_class(self):
 
 
 @inherit_doc
-class HashingTF(JavaTransformer, HasInputCol, HasOutputCol):
+class HashingTF(JavaTransformer, HasInputCol, HasOutputCol, HasNumFeatures):
 
     def __init__(self):
         super(HashingTF, self).__init__()
-        #: param for number of features
-        self.numFeatures = Param(self, "numFeatures", "number of features", 1 << 18)
 
     @property
     def _java_class(self):
         return "org.apache.spark.ml.feature.HashingTF"
-
-    def setNumFeatures(self, value):
-        self.paramMap[self.numFeatures] = value
-        return self
-
-    def getNumFeatures(self):
-        if self.numFeatures in self.paramMap:
-            return self.paramMap[self.numFeatures]
-        else:
-            return self.numFeatures.defaultValue

python/pyspark/ml/param/__init__.py

@@ -36,7 +36,7 @@ def __init__(self, parent, name, doc, defaultValue=None):
         self.defaultValue = defaultValue
 
     def __str__(self):
-        return str(self.parent) + "_" + self.name
+        return str(self.parent) + "-" + self.name
 
     def __repr__(self):
         return "Param(parent=%r, name=%r, doc=%r, defaultValue=%r)" % \

python/pyspark/ml/param/_gen_shared_params.py

@@ -90,7 +90,8 @@ def get$Name(self):
         ("labelCol", "label column name", "'label'"),
         ("predictionCol", "prediction column name", "'prediction'"),
         ("inputCol", "input column name", "'input'"),
-        ("outputCol", "output column name", "'output'")]
+        ("outputCol", "output column name", "'output'"),
+        ("numFeatures", "number of features", "1 << 18")]
     code = []
     for name, doc, defaultValue in shared:
         code.append(_gen_param_code(name, doc, defaultValue))

python/pyspark/ml/param/shared.py

@@ -228,3 +228,33 @@ def getOutputCol(self):
             return self.paramMap[self.outputCol]
         else:
             return self.outputCol.defaultValue
+
+
+class HasNumFeatures(Params):
+    """
+    Params with numFeatures.
+    """
+
+    # a placeholder to make it appear in the generated doc
+    numFeatures = Param(Params._dummy(), "numFeatures", "number of features", 1 << 18)
+
+    def __init__(self):
+        super(HasNumFeatures, self).__init__()
+        #: param for number of features
+        self.numFeatures = Param(self, "numFeatures", "number of features", 1 << 18)
+
+    def setNumFeatures(self, value):
+        """
+        Sets the value of :py:attr:`numFeatures`.
+        """
+        self.paramMap[self.numFeatures] = value
+        return self
+
+    def getNumFeatures(self):
+        """
+        Gets the value of numFeatures or its default value.
+        """
+        if self.numFeatures in self.paramMap:
+            return self.paramMap[self.numFeatures]
+        else:
+            return self.numFeatures.defaultValue