74 lines
2.0 KiB
Java
74 lines
2.0 KiB
Java
package com.zhgd.xmgl.util;
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import java.util.ArrayList;
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import java.util.Optional;
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public class PolygonUtil {
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/**
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* 五边形面积
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*
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* @param r 从五边形中心到顶点的距离，计算五边形的面积
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* @return
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*/
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public static double pentagonArea(double r) {
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double s = 2 * r * Math.sin(Math.PI / 5);
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return (5 * Math.pow(s, 2)) / (4 * Math.tan(Math.PI / 5));
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}
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/**
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* 八边形面积
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*
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* @param r
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* @return
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*/
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public static double octagonArea(double r) {
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double s = 2 * r * Math.sin(Math.PI / 8);
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return (8 * Math.pow(s, 2)) / (4 * Math.tan(Math.PI / 8));
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}
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/**
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* 多边形面积
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*
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* @param r
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* @return
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*/
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public static double polygonArea(double r, int edgeNum) {
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double s = 2 * r * Math.sin(Math.PI / edgeNum);
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return (edgeNum * Math.pow(s, 2)) / (4 * Math.tan(Math.PI / edgeNum));
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}
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/**
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* 计算雷达图面积
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*
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* @param r 从多边形中心到顶点的距离
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* @param edgeNum 边数
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* @param data 三角形的边长
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* @return
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*/
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public static double calRadioArea(double r, int edgeNum, Double... data) {
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double sinVal = Math.sin(Math.toRadians(360.0 / edgeNum));
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ArrayList<Double> dataList = new ArrayList<>();
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for (Double d : data) {
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dataList.add(Optional.ofNullable(d).orElse(0.0));
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}
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ArrayList<Double> doubles = new ArrayList<>();
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for (int i = 0; i < edgeNum; i++) {
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double r1;
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if (i == edgeNum - 1) {
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r1 = dataList.get(i) * dataList.get(0) * sinVal / 2;
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} else {
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r1 = dataList.get(i) * dataList.get(i + 1) * sinVal / 2;
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}
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doubles.add(r1);
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}
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double sum = doubles.stream().mapToDouble(value -> value).sum();
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return sum / polygonArea(r, edgeNum);
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}
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public static void main(String[] args) {
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System.out.println(calRadioArea(1, 5, 1.0, 1.0, 1.0, 1.0, 1.0));
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}
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}
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