org.apache.spark.ml.linalg.JsonMatrixConverter.scala Maven / Gradle / Ivy
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* 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,
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* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.spark.ml.linalg
import org.json4s.DefaultFormats
import org.json4s.JsonDSL._
import org.json4s.jackson.JsonMethods.{compact, parse => parseJson, render}
private[ml] object JsonMatrixConverter {
/** Unique class name for identifying JSON object encoded by this class. */
val className = "matrix"
/**
* Parses the JSON representation of a Matrix into a [[Matrix]].
*/
def fromJson(json: String): Matrix = {
implicit val formats = DefaultFormats
val jValue = parseJson(json)
(jValue \ "type").extract[Int] match {
case 0 => // sparse
val numRows = (jValue \ "numRows").extract[Int]
val numCols = (jValue \ "numCols").extract[Int]
val colPtrs = (jValue \ "colPtrs").extract[Seq[Int]].toArray
val rowIndices = (jValue \ "rowIndices").extract[Seq[Int]].toArray
val values = (jValue \ "values").extract[Seq[Double]].toArray
val isTransposed = (jValue \ "isTransposed").extract[Boolean]
new SparseMatrix(numRows, numCols, colPtrs, rowIndices, values, isTransposed)
case 1 => // dense
val numRows = (jValue \ "numRows").extract[Int]
val numCols = (jValue \ "numCols").extract[Int]
val values = (jValue \ "values").extract[Seq[Double]].toArray
val isTransposed = (jValue \ "isTransposed").extract[Boolean]
new DenseMatrix(numRows, numCols, values, isTransposed)
case _ =>
throw new IllegalArgumentException(s"Cannot parse $json into a Matrix.")
}
}
/**
* Coverts the Matrix to a JSON string.
*/
def toJson(m: Matrix): String = {
m match {
case SparseMatrix(numRows, numCols, colPtrs, rowIndices, values, isTransposed) =>
val jValue = ("class" -> className) ~
("type" -> 0) ~
("numRows" -> numRows) ~
("numCols" -> numCols) ~
("colPtrs" -> colPtrs.toSeq) ~
("rowIndices" -> rowIndices.toSeq) ~
("values" -> values.toSeq) ~
("isTransposed" -> isTransposed)
compact(render(jValue))
case DenseMatrix(numRows, numCols, values, isTransposed) =>
val jValue = ("class" -> className) ~
("type" -> 1) ~
("numRows" -> numRows) ~
("numCols" -> numCols) ~
("values" -> values.toSeq) ~
("isTransposed" -> isTransposed)
compact(render(jValue))
case _ =>
throw new IllegalArgumentException(s"Unknown matrix type ${m.getClass}.")
}
}
}