Here you can find the source of getMinimums(List
public static List<Double> getMinimums(List<Double> data)
//package com.java2s; /************************************************************************************** Copyright 2015 Applied Research Associates, Inc. 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:/* w ww .j ava2s . com*/ 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. **************************************************************************************/ import java.util.ArrayList; import java.util.List; public class Main { public static List<Double> getMinimums(List<Double> data) { List<Double> xMin = new ArrayList<Double>(); List<Double> yMin = new ArrayList<Double>(); List<Double> xMax = new ArrayList<Double>(); List<Double> yMax = new ArrayList<Double>(); getPeriodBounds(data, data, xMin, yMin, xMax, yMax); return xMin; } public static void getPeriodBounds(List<Double> xData, List<Double> yData, List<Double> xMin, List<Double> yMin, List<Double> xMax, List<Double> yMax) { if (xData.size() != yData.size()) throw new RuntimeException("Waveform x and y data not the same size"); xMin.clear(); yMin.clear(); xMax.clear(); yMax.clear(); // Ride the y value, and save off the min/max when we hit one, and the x value at those points double p1, p2; Boolean looking4max = null; for (int i = 1; i < yData.size(); i++) { p1 = yData.get(i - 1); p2 = yData.get(i); if (p1 == p2) continue; if (p2 > p1) { looking4max = true; break; } if (p1 > p2) { looking4max = false; break; } } if (looking4max != null) { for (int i = 1; i < yData.size(); i++) { p1 = yData.get(i - 1); p2 = yData.get(i); if (p1 == p2) continue; if (looking4max && p2 < p1) { looking4max = false; xMax.add(xData.get(i - 1)); yMax.add(p1); } if (!looking4max && p2 > p1) { looking4max = true; xMin.add(xData.get(i - 1)); yMin.add(p1); } } } else// All the values are the same! { yMin.add(yData.get(0)); yMax.add(yData.get(0)); xMin.add(xData.get(0)); xMax.add(xData.get(0)); } } }