DCT¶
-
class
pyspark.ml.feature.
DCT
(inverse=False, inputCol=None, outputCol=None)[source]¶ A feature transformer that takes the 1D discrete cosine transform of a real vector. No zero padding is performed on the input vector. It returns a real vector of the same length representing the DCT. The return vector is scaled such that the transform matrix is unitary (aka scaled DCT-II).
See also
>>> from pyspark.ml.linalg import Vectors >>> df1 = spark.createDataFrame([(Vectors.dense([5.0, 8.0, 6.0]),)], ["vec"]) >>> dct = DCT( ) >>> dct.setInverse(False) DCT... >>> dct.setInputCol("vec") DCT... >>> dct.setOutputCol("resultVec") DCT... >>> df2 = dct.transform(df1) >>> df2.head().resultVec DenseVector([10.969..., -0.707..., -2.041...]) >>> df3 = DCT(inverse=True, inputCol="resultVec", outputCol="origVec").transform(df2) >>> df3.head().origVec DenseVector([5.0, 8.0, 6.0]) >>> dctPath = temp_path + "/dct" >>> dct.save(dctPath) >>> loadedDtc = DCT.load(dctPath) >>> loadedDtc.getInverse() False
New in version 1.6.0.
Methods
Attributes
Methods Documentation
-
clear
(param)¶ Clears a param from the param map if it has been explicitly set.
-
copy
(extra=None)¶ Creates a copy of this instance with the same uid and some extra params. This implementation first calls Params.copy and then make a copy of the companion Java pipeline component with extra params. So both the Python wrapper and the Java pipeline component get copied.
- Parameters
extra – Extra parameters to copy to the new instance
- Returns
Copy of this instance
-
explainParam
(param)¶ Explains a single param and returns its name, doc, and optional default value and user-supplied value in a string.
-
explainParams
()¶ Returns the documentation of all params with their optionally default values and user-supplied values.
-
extractParamMap
(extra=None)¶ Extracts the embedded default param values and user-supplied values, and then merges them with extra values from input into a flat param map, where the latter value is used if there exist conflicts, i.e., with ordering: default param values < user-supplied values < extra.
- Parameters
extra – extra param values
- Returns
merged param map
-
getInputCol
()¶ Gets the value of inputCol or its default value.
-
getOrDefault
(param)¶ Gets the value of a param in the user-supplied param map or its default value. Raises an error if neither is set.
-
getOutputCol
()¶ Gets the value of outputCol or its default value.
-
getParam
(paramName)¶ Gets a param by its name.
-
hasDefault
(param)¶ Checks whether a param has a default value.
-
hasParam
(paramName)¶ Tests whether this instance contains a param with a given (string) name.
-
isDefined
(param)¶ Checks whether a param is explicitly set by user or has a default value.
-
isSet
(param)¶ Checks whether a param is explicitly set by user.
-
classmethod
load
(path)¶ Reads an ML instance from the input path, a shortcut of read().load(path).
-
classmethod
read
()¶ Returns an MLReader instance for this class.
-
save
(path)¶ Save this ML instance to the given path, a shortcut of ‘write().save(path)’.
-
set
(param, value)¶ Sets a parameter in the embedded param map.
-
setParams
(self, inverse=False, inputCol=None, outputCol=None)[source]¶ Sets params for this DCT.
New in version 1.6.0.
-
transform
(dataset, params=None)¶ Transforms the input dataset with optional parameters.
- Parameters
dataset – input dataset, which is an instance of
pyspark.sql.DataFrame
params – an optional param map that overrides embedded params.
- Returns
transformed dataset
New in version 1.3.0.
-
write
()¶ Returns an MLWriter instance for this ML instance.
Attributes Documentation
-
inputCol
= Param(parent='undefined', name='inputCol', doc='input column name.')¶
-
inverse
= Param(parent='undefined', name='inverse', doc='Set transformer to perform inverse DCT, default False.')¶
-
outputCol
= Param(parent='undefined', name='outputCol', doc='output column name.')¶
-
params
¶ Returns all params ordered by name. The default implementation uses
dir()
to get all attributes of typeParam
.
-