/*
 * Artificial Intelligence for Humans
 * Volume 1: Fundamental Algorithms
 * Scala Version
 * http://www.aifh.org
 * http://www.jeffheaton.com
 *
 * Code repository:
 * https://github.com/jeffheaton/aifh

 * Copyright 2013 by Jeff Heaton
 *
 * Licensed 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.
 *
 * For more information on Heaton Research copyrights, licenses
 * and trademarks visit:
 * http://www.heatonresearch.com/copyright
 */
package com.heatonresearch.aifh.error

/**
 * Calculates the error as the square root of the average of the sum of the squared differences between the actual and
 * ideal vectors.
 * <p/>
 * http://www.heatonresearch.com/wiki/Root_Mean_Square_Error
 */
class ErrorCalculationRMS extends AbstractErrorCalculation {
  /**
   * Calculate the error with RMS.
   *
   * @return The current error for the neural network.
   */
  override def calculate: Double = {
    if (setSize == 0)
      Double.PositiveInfinity
    else
      Math.sqrt(globalError / setSize)
  }
}