| # |
| # Licensed to the Apache Software Foundation (ASF) under one or more |
| # contributor license agreements. See the NOTICE file distributed with |
| # this work for additional information regarding copyright ownership. |
| # The ASF licenses this file to You under the Apache License, Version 2.0 |
| # (the "License"); you may not use this file except in compliance with |
| # the License. You may obtain a copy of the License at |
| # |
| # http://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, software |
| # distributed under the License is distributed on an "AS IS" BASIS, |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| # See the License for the specific language governing permissions and |
| # limitations under the License. |
| # |
| |
| from pyspark import keyword_only, since |
| from pyspark.sql import DataFrame |
| from pyspark.ml.util import * |
| from pyspark.ml.wrapper import JavaEstimator, JavaModel, JavaParams, _jvm |
| from pyspark.ml.param.shared import * |
| |
| __all__ = ["FPGrowth", "FPGrowthModel", "PrefixSpan"] |
| |
| |
| class HasMinSupport(Params): |
| """ |
| Mixin for param minSupport. |
| """ |
| |
| minSupport = Param( |
| Params._dummy(), |
| "minSupport", |
| "Minimal support level of the frequent pattern. [0.0, 1.0]. " + |
| "Any pattern that appears more than (minSupport * size-of-the-dataset) " + |
| "times will be output in the frequent itemsets.", |
| typeConverter=TypeConverters.toFloat) |
| |
| def setMinSupport(self, value): |
| """ |
| Sets the value of :py:attr:`minSupport`. |
| """ |
| return self._set(minSupport=value) |
| |
| def getMinSupport(self): |
| """ |
| Gets the value of minSupport or its default value. |
| """ |
| return self.getOrDefault(self.minSupport) |
| |
| |
| class HasNumPartitions(Params): |
| """ |
| Mixin for param numPartitions: Number of partitions (at least 1) used by parallel FP-growth. |
| """ |
| |
| numPartitions = Param( |
| Params._dummy(), |
| "numPartitions", |
| "Number of partitions (at least 1) used by parallel FP-growth. " + |
| "By default the param is not set, " + |
| "and partition number of the input dataset is used.", |
| typeConverter=TypeConverters.toInt) |
| |
| def setNumPartitions(self, value): |
| """ |
| Sets the value of :py:attr:`numPartitions`. |
| """ |
| return self._set(numPartitions=value) |
| |
| def getNumPartitions(self): |
| """ |
| Gets the value of :py:attr:`numPartitions` or its default value. |
| """ |
| return self.getOrDefault(self.numPartitions) |
| |
| |
| class HasMinConfidence(Params): |
| """ |
| Mixin for param minConfidence. |
| """ |
| |
| minConfidence = Param( |
| Params._dummy(), |
| "minConfidence", |
| "Minimal confidence for generating Association Rule. [0.0, 1.0]. " + |
| "minConfidence will not affect the mining for frequent itemsets, " + |
| "but will affect the association rules generation.", |
| typeConverter=TypeConverters.toFloat) |
| |
| def setMinConfidence(self, value): |
| """ |
| Sets the value of :py:attr:`minConfidence`. |
| """ |
| return self._set(minConfidence=value) |
| |
| def getMinConfidence(self): |
| """ |
| Gets the value of minConfidence or its default value. |
| """ |
| return self.getOrDefault(self.minConfidence) |
| |
| |
| class HasItemsCol(Params): |
| """ |
| Mixin for param itemsCol: items column name. |
| """ |
| |
| itemsCol = Param(Params._dummy(), "itemsCol", |
| "items column name", typeConverter=TypeConverters.toString) |
| |
| def setItemsCol(self, value): |
| """ |
| Sets the value of :py:attr:`itemsCol`. |
| """ |
| return self._set(itemsCol=value) |
| |
| def getItemsCol(self): |
| """ |
| Gets the value of itemsCol or its default value. |
| """ |
| return self.getOrDefault(self.itemsCol) |
| |
| |
| class FPGrowthModel(JavaModel, JavaMLWritable, JavaMLReadable): |
| """ |
| .. note:: Experimental |
| |
| Model fitted by FPGrowth. |
| |
| .. versionadded:: 2.2.0 |
| """ |
| @property |
| @since("2.2.0") |
| def freqItemsets(self): |
| """ |
| DataFrame with two columns: |
| * `items` - Itemset of the same type as the input column. |
| * `freq` - Frequency of the itemset (`LongType`). |
| """ |
| return self._call_java("freqItemsets") |
| |
| @property |
| @since("2.2.0") |
| def associationRules(self): |
| """ |
| DataFrame with four columns: |
| * `antecedent` - Array of the same type as the input column. |
| * `consequent` - Array of the same type as the input column. |
| * `confidence` - Confidence for the rule (`DoubleType`). |
| * `lift` - Lift for the rule (`DoubleType`). |
| """ |
| return self._call_java("associationRules") |
| |
| |
| class FPGrowth(JavaEstimator, HasItemsCol, HasPredictionCol, |
| HasMinSupport, HasNumPartitions, HasMinConfidence, |
| JavaMLWritable, JavaMLReadable): |
| |
| r""" |
| .. note:: Experimental |
| |
| A parallel FP-growth algorithm to mine frequent itemsets. The algorithm is described in |
| Li et al., PFP: Parallel FP-Growth for Query Recommendation [LI2008]_. |
| PFP distributes computation in such a way that each worker executes an |
| independent group of mining tasks. The FP-Growth algorithm is described in |
| Han et al., Mining frequent patterns without candidate generation [HAN2000]_ |
| |
| .. [LI2008] http://dx.doi.org/10.1145/1454008.1454027 |
| .. [HAN2000] http://dx.doi.org/10.1145/335191.335372 |
| |
| .. note:: null values in the feature column are ignored during fit(). |
| .. note:: Internally `transform` `collects` and `broadcasts` association rules. |
| |
| >>> from pyspark.sql.functions import split |
| >>> data = (spark.read |
| ... .text("data/mllib/sample_fpgrowth.txt") |
| ... .select(split("value", "\s+").alias("items"))) |
| >>> data.show(truncate=False) |
| +------------------------+ |
| |items | |
| +------------------------+ |
| |[r, z, h, k, p] | |
| |[z, y, x, w, v, u, t, s]| |
| |[s, x, o, n, r] | |
| |[x, z, y, m, t, s, q, e]| |
| |[z] | |
| |[x, z, y, r, q, t, p] | |
| +------------------------+ |
| >>> fp = FPGrowth(minSupport=0.2, minConfidence=0.7) |
| >>> fpm = fp.fit(data) |
| >>> fpm.freqItemsets.show(5) |
| +---------+----+ |
| | items|freq| |
| +---------+----+ |
| | [s]| 3| |
| | [s, x]| 3| |
| |[s, x, z]| 2| |
| | [s, z]| 2| |
| | [r]| 3| |
| +---------+----+ |
| only showing top 5 rows |
| >>> fpm.associationRules.show(5) |
| +----------+----------+----------+ |
| |antecedent|consequent|confidence| |
| +----------+----------+----------+ |
| | [t, s]| [y]| 1.0| |
| | [t, s]| [x]| 1.0| |
| | [t, s]| [z]| 1.0| |
| | [p]| [r]| 1.0| |
| | [p]| [z]| 1.0| |
| +----------+----------+----------+ |
| only showing top 5 rows |
| >>> new_data = spark.createDataFrame([(["t", "s"], )], ["items"]) |
| >>> sorted(fpm.transform(new_data).first().prediction) |
| ['x', 'y', 'z'] |
| |
| .. versionadded:: 2.2.0 |
| """ |
| @keyword_only |
| def __init__(self, minSupport=0.3, minConfidence=0.8, itemsCol="items", |
| predictionCol="prediction", numPartitions=None): |
| """ |
| __init__(self, minSupport=0.3, minConfidence=0.8, itemsCol="items", \ |
| predictionCol="prediction", numPartitions=None) |
| """ |
| super(FPGrowth, self).__init__() |
| self._java_obj = self._new_java_obj("org.apache.spark.ml.fpm.FPGrowth", self.uid) |
| self._setDefault(minSupport=0.3, minConfidence=0.8, |
| itemsCol="items", predictionCol="prediction") |
| kwargs = self._input_kwargs |
| self.setParams(**kwargs) |
| |
| @keyword_only |
| @since("2.2.0") |
| def setParams(self, minSupport=0.3, minConfidence=0.8, itemsCol="items", |
| predictionCol="prediction", numPartitions=None): |
| """ |
| setParams(self, minSupport=0.3, minConfidence=0.8, itemsCol="items", \ |
| predictionCol="prediction", numPartitions=None) |
| """ |
| kwargs = self._input_kwargs |
| return self._set(**kwargs) |
| |
| def _create_model(self, java_model): |
| return FPGrowthModel(java_model) |
| |
| |
| class PrefixSpan(JavaParams): |
| """ |
| .. note:: Experimental |
| |
| A parallel PrefixSpan algorithm to mine frequent sequential patterns. |
| The PrefixSpan algorithm is described in J. Pei, et al., PrefixSpan: Mining Sequential Patterns |
| Efficiently by Prefix-Projected Pattern Growth |
| (see <a href="http://doi.org/10.1109/ICDE.2001.914830">here</a>). |
| This class is not yet an Estimator/Transformer, use :py:func:`findFrequentSequentialPatterns` |
| method to run the PrefixSpan algorithm. |
| |
| @see <a href="https://en.wikipedia.org/wiki/Sequential_Pattern_Mining">Sequential Pattern Mining |
| (Wikipedia)</a> |
| .. versionadded:: 2.4.0 |
| |
| """ |
| |
| minSupport = Param(Params._dummy(), "minSupport", "The minimal support level of the " + |
| "sequential pattern. Sequential pattern that appears more than " + |
| "(minSupport * size-of-the-dataset) times will be output. Must be >= 0.", |
| typeConverter=TypeConverters.toFloat) |
| |
| maxPatternLength = Param(Params._dummy(), "maxPatternLength", |
| "The maximal length of the sequential pattern. Must be > 0.", |
| typeConverter=TypeConverters.toInt) |
| |
| maxLocalProjDBSize = Param(Params._dummy(), "maxLocalProjDBSize", |
| "The maximum number of items (including delimiters used in the " + |
| "internal storage format) allowed in a projected database before " + |
| "local processing. If a projected database exceeds this size, " + |
| "another iteration of distributed prefix growth is run. " + |
| "Must be > 0.", |
| typeConverter=TypeConverters.toInt) |
| |
| sequenceCol = Param(Params._dummy(), "sequenceCol", "The name of the sequence column in " + |
| "dataset, rows with nulls in this column are ignored.", |
| typeConverter=TypeConverters.toString) |
| |
| @keyword_only |
| def __init__(self, minSupport=0.1, maxPatternLength=10, maxLocalProjDBSize=32000000, |
| sequenceCol="sequence"): |
| """ |
| __init__(self, minSupport=0.1, maxPatternLength=10, maxLocalProjDBSize=32000000, \ |
| sequenceCol="sequence") |
| """ |
| super(PrefixSpan, self).__init__() |
| self._java_obj = self._new_java_obj("org.apache.spark.ml.fpm.PrefixSpan", self.uid) |
| self._setDefault(minSupport=0.1, maxPatternLength=10, maxLocalProjDBSize=32000000, |
| sequenceCol="sequence") |
| kwargs = self._input_kwargs |
| self.setParams(**kwargs) |
| |
| @keyword_only |
| @since("2.4.0") |
| def setParams(self, minSupport=0.1, maxPatternLength=10, maxLocalProjDBSize=32000000, |
| sequenceCol="sequence"): |
| """ |
| setParams(self, minSupport=0.1, maxPatternLength=10, maxLocalProjDBSize=32000000, \ |
| sequenceCol="sequence") |
| """ |
| kwargs = self._input_kwargs |
| return self._set(**kwargs) |
| |
| @since("2.4.0") |
| def findFrequentSequentialPatterns(self, dataset): |
| """ |
| .. note:: Experimental |
| |
| Finds the complete set of frequent sequential patterns in the input sequences of itemsets. |
| |
| :param dataset: A dataframe containing a sequence column which is |
| `ArrayType(ArrayType(T))` type, T is the item type for the input dataset. |
| :return: A `DataFrame` that contains columns of sequence and corresponding frequency. |
| The schema of it will be: |
| - `sequence: ArrayType(ArrayType(T))` (T is the item type) |
| - `freq: Long` |
| |
| >>> from pyspark.ml.fpm import PrefixSpan |
| >>> from pyspark.sql import Row |
| >>> df = sc.parallelize([Row(sequence=[[1, 2], [3]]), |
| ... Row(sequence=[[1], [3, 2], [1, 2]]), |
| ... Row(sequence=[[1, 2], [5]]), |
| ... Row(sequence=[[6]])]).toDF() |
| >>> prefixSpan = PrefixSpan(minSupport=0.5, maxPatternLength=5) |
| >>> prefixSpan.findFrequentSequentialPatterns(df).sort("sequence").show(truncate=False) |
| +----------+----+ |
| |sequence |freq| |
| +----------+----+ |
| |[[1]] |3 | |
| |[[1], [3]]|2 | |
| |[[1, 2]] |3 | |
| |[[2]] |3 | |
| |[[3]] |2 | |
| +----------+----+ |
| |
| .. versionadded:: 2.4.0 |
| """ |
| self._transfer_params_to_java() |
| jdf = self._java_obj.findFrequentSequentialPatterns(dataset._jdf) |
| return DataFrame(jdf, dataset.sql_ctx) |