content: /**
   * 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.bigtop.datagenerators.samplers.pdfs;
  
  public class GaussianPDF implements ProbabilityDensityFunction<Double>
  {
  	private double mean;
  	private double std;
  
  	public GaussianPDF(double mean, double std)
  	{
  		this.mean = mean;
  		this.std = std;
  	}
  
  	public double probability(Double value)
  	{
  		double diff = (mean - value) * (mean - value);
  		double var = std * std;
  		double exp = Math.exp(-1.0 * diff / (2.0 * var));
  
  		return exp / (std * Math.sqrt(2.0 * Math.PI));
  	}
  }
  