Python pyspark VectorAssembler用法及代碼示例

>>> df = spark.createDataFrame([(1, 0, 3)], ["a", "b", "c"])
>>> vecAssembler = VectorAssembler(outputCol="features")
>>> vecAssembler.setInputCols(["a", "b", "c"])
VectorAssembler...
>>> vecAssembler.transform(df).head().features
DenseVector([1.0, 0.0, 3.0])
>>> vecAssembler.setParams(outputCol="freqs").transform(df).head().freqs
DenseVector([1.0, 0.0, 3.0])
>>> params = {vecAssembler.inputCols: ["b", "a"], vecAssembler.outputCol: "vector"}
>>> vecAssembler.transform(df, params).head().vector
DenseVector([0.0, 1.0])
>>> vectorAssemblerPath = temp_path + "/vector-assembler"
>>> vecAssembler.save(vectorAssemblerPath)
>>> loadedAssembler = VectorAssembler.load(vectorAssemblerPath)
>>> loadedAssembler.transform(df).head().freqs == vecAssembler.transform(df).head().freqs
True
>>> dfWithNullsAndNaNs = spark.createDataFrame(
...    [(1.0, 2.0, None), (3.0, float("nan"), 4.0), (5.0, 6.0, 7.0)], ["a", "b", "c"])
>>> vecAssembler2 = VectorAssembler(inputCols=["a", "b", "c"], outputCol="features",
...    handleInvalid="keep")
>>> vecAssembler2.transform(dfWithNullsAndNaNs).show()
+---+---+----+-------------+
|  a|  b|   c|     features|
+---+---+----+-------------+
|1.0|2.0|null|[1.0,2.0,NaN]|
|3.0|NaN| 4.0|[3.0,NaN,4.0]|
|5.0|6.0| 7.0|[5.0,6.0,7.0]|
+---+---+----+-------------+
...
>>> vecAssembler2.setParams(handleInvalid="skip").transform(dfWithNullsAndNaNs).show()
+---+---+---+-------------+
|  a|  b|  c|     features|
+---+---+---+-------------+
|5.0|6.0|7.0|[5.0,6.0,7.0]|
+---+---+---+-------------+
...