spark SquaredError 源码
spark SquaredError 代码
文件路径：/mllib/src/main/scala/org/apache/spark/mllib/tree/loss/SquaredError.scala
/*
* 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.mllib.tree.loss
import org.apache.spark.annotation.Since
/**
* Class for squared error loss calculation.
*
* The squared (L2) error is defined as:
* (y - F(x))**2
* where y is the label and F(x) is the model prediction for features x.
*/
@Since("1.2.0")
object SquaredError extends Loss {
/**
* Method to calculate the gradients for the gradient boosting calculation for least
* squares error calculation.
* The gradient with respect to F(x) is: - 2 (y - F(x))
* @param prediction Predicted label.
* @param label True label.
* @return Loss gradient
*/
@Since("1.2.0")
override def gradient(prediction: Double, label: Double): Double = {
- 2.0 * (label - prediction)
}
override private[spark] def computeError(prediction: Double, label: Double): Double = {
val err = label - prediction
err * err
}
}
相关信息
相关文章
0
赞
- 所属分类： 前端技术
- 本文标签：
热门推荐
-
2、 - 优质文章
-
3、 gate.io
-
8、 golang
-
9、 openharmony
-
10、 Vue中input框自动聚焦