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Diffstat (limited to 'mllib/src/main/scala/org/apache/spark/ml/attribute/AttributeGroup.scala')
-rw-r--r-- | mllib/src/main/scala/org/apache/spark/ml/attribute/AttributeGroup.scala | 234 |
1 files changed, 234 insertions, 0 deletions
diff --git a/mllib/src/main/scala/org/apache/spark/ml/attribute/AttributeGroup.scala b/mllib/src/main/scala/org/apache/spark/ml/attribute/AttributeGroup.scala new file mode 100644 index 0000000000..970e6ad551 --- /dev/null +++ b/mllib/src/main/scala/org/apache/spark/ml/attribute/AttributeGroup.scala @@ -0,0 +1,234 @@ +/* + * 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. + */ + +package org.apache.spark.ml.attribute + +import scala.collection.mutable.ArrayBuffer + +import org.apache.spark.mllib.linalg.VectorUDT +import org.apache.spark.sql.types.{Metadata, MetadataBuilder, StructField} + +/** + * Attributes that describe a vector ML column. + * + * @param name name of the attribute group (the ML column name) + * @param numAttributes optional number of attributes. At most one of `numAttributes` and `attrs` + * can be defined. + * @param attrs optional array of attributes. Attribute will be copied with their corresponding + * indices in the array. + */ +class AttributeGroup private ( + val name: String, + val numAttributes: Option[Int], + attrs: Option[Array[Attribute]]) extends Serializable { + + require(name.nonEmpty, "Cannot have an empty string for name.") + require(!(numAttributes.isDefined && attrs.isDefined), + "Cannot have both numAttributes and attrs defined.") + + /** + * Creates an attribute group without attribute info. + * @param name name of the attribute group + */ + def this(name: String) = this(name, None, None) + + /** + * Creates an attribute group knowing only the number of attributes. + * @param name name of the attribute group + * @param numAttributes number of attributes + */ + def this(name: String, numAttributes: Int) = this(name, Some(numAttributes), None) + + /** + * Creates an attribute group with attributes. + * @param name name of the attribute group + * @param attrs array of attributes. Attributes will be copied with their corresponding indices in + * the array. + */ + def this(name: String, attrs: Array[Attribute]) = this(name, None, Some(attrs)) + + /** + * Optional array of attributes. At most one of `numAttributes` and `attributes` can be defined. + */ + val attributes: Option[Array[Attribute]] = attrs.map(_.view.zipWithIndex.map { case (attr, i) => + attr.withIndex(i) + }.toArray) + + private lazy val nameToIndex: Map[String, Int] = { + attributes.map(_.view.flatMap { attr => + attr.name.map(_ -> attr.index.get) + }.toMap).getOrElse(Map.empty) + } + + /** Size of the attribute group. Returns -1 if the size is unknown. */ + def size: Int = { + if (numAttributes.isDefined) { + numAttributes.get + } else if (attributes.isDefined) { + attributes.get.length + } else { + -1 + } + } + + /** Test whether this attribute group contains a specific attribute. */ + def hasAttr(attrName: String): Boolean = nameToIndex.contains(attrName) + + /** Index of an attribute specified by name. */ + def indexOf(attrName: String): Int = nameToIndex(attrName) + + /** Gets an attribute by its name. */ + def apply(attrName: String): Attribute = { + attributes.get(indexOf(attrName)) + } + + /** Gets an attribute by its name. */ + def getAttr(attrName: String): Attribute = this(attrName) + + /** Gets an attribute by its index. */ + def apply(attrIndex: Int): Attribute = attributes.get(attrIndex) + + /** Gets an attribute by its index. */ + def getAttr(attrIndex: Int): Attribute = this(attrIndex) + + /** Converts to metadata without name. */ + private[attribute] def toMetadata: Metadata = { + import AttributeKeys._ + val bldr = new MetadataBuilder() + if (attributes.isDefined) { + val numericMetadata = ArrayBuffer.empty[Metadata] + val nominalMetadata = ArrayBuffer.empty[Metadata] + val binaryMetadata = ArrayBuffer.empty[Metadata] + attributes.get.foreach { + case numeric: NumericAttribute => + // Skip default numeric attributes. + if (numeric.withoutIndex != NumericAttribute.defaultAttr) { + numericMetadata += numeric.toMetadata(withType = false) + } + case nominal: NominalAttribute => + nominalMetadata += nominal.toMetadata(withType = false) + case binary: BinaryAttribute => + binaryMetadata += binary.toMetadata(withType = false) + } + val attrBldr = new MetadataBuilder + if (numericMetadata.nonEmpty) { + attrBldr.putMetadataArray(AttributeType.Numeric.name, numericMetadata.toArray) + } + if (nominalMetadata.nonEmpty) { + attrBldr.putMetadataArray(AttributeType.Nominal.name, nominalMetadata.toArray) + } + if (binaryMetadata.nonEmpty) { + attrBldr.putMetadataArray(AttributeType.Binary.name, binaryMetadata.toArray) + } + bldr.putMetadata(ATTRIBUTES, attrBldr.build()) + bldr.putLong(NUM_ATTRIBUTES, attributes.get.length) + } else if (numAttributes.isDefined) { + bldr.putLong(NUM_ATTRIBUTES, numAttributes.get) + } + bldr.build() + } + + /** Converts to a StructField with some existing metadata. */ + def toStructField(existingMetadata: Metadata): StructField = { + val newMetadata = new MetadataBuilder() + .withMetadata(existingMetadata) + .putMetadata(AttributeKeys.ML_ATTR, toMetadata) + .build() + StructField(name, new VectorUDT, nullable = false, newMetadata) + } + + /** Converts to a StructField. */ + def toStructField(): StructField = toStructField(Metadata.empty) + + override def equals(other: Any): Boolean = { + other match { + case o: AttributeGroup => + (name == o.name) && + (numAttributes == o.numAttributes) && + (attributes.map(_.toSeq) == o.attributes.map(_.toSeq)) + case _ => + false + } + } + + override def hashCode: Int = { + var sum = 17 + sum = 37 * sum + name.hashCode + sum = 37 * sum + numAttributes.hashCode + sum = 37 * sum + attributes.map(_.toSeq).hashCode + sum + } +} + +/** Factory methods to create attribute groups. */ +object AttributeGroup { + + import AttributeKeys._ + + /** Creates an attribute group from a [[Metadata]] instance with name. */ + private[attribute] def fromMetadata(metadata: Metadata, name: String): AttributeGroup = { + import org.apache.spark.ml.attribute.AttributeType._ + if (metadata.contains(ATTRIBUTES)) { + val numAttrs = metadata.getLong(NUM_ATTRIBUTES).toInt + val attributes = new Array[Attribute](numAttrs) + val attrMetadata = metadata.getMetadata(ATTRIBUTES) + if (attrMetadata.contains(Numeric.name)) { + attrMetadata.getMetadataArray(Numeric.name) + .map(NumericAttribute.fromMetadata) + .foreach { attr => + attributes(attr.index.get) = attr + } + } + if (attrMetadata.contains(Nominal.name)) { + attrMetadata.getMetadataArray(Nominal.name) + .map(NominalAttribute.fromMetadata) + .foreach { attr => + attributes(attr.index.get) = attr + } + } + if (attrMetadata.contains(Binary.name)) { + attrMetadata.getMetadataArray(Binary.name) + .map(BinaryAttribute.fromMetadata) + .foreach { attr => + attributes(attr.index.get) = attr + } + } + var i = 0 + while (i < numAttrs) { + if (attributes(i) == null) { + attributes(i) = NumericAttribute.defaultAttr + } + i += 1 + } + new AttributeGroup(name, attributes) + } else if (metadata.contains(NUM_ATTRIBUTES)) { + new AttributeGroup(name, metadata.getLong(NUM_ATTRIBUTES).toInt) + } else { + new AttributeGroup(name) + } + } + + /** Creates an attribute group from a [[StructField]] instance. */ + def fromStructField(field: StructField): AttributeGroup = { + require(field.dataType == new VectorUDT) + if (field.metadata.contains(ML_ATTR)) { + fromMetadata(field.metadata.getMetadata(ML_ATTR), field.name) + } else { + new AttributeGroup(field.name) + } + } +} |