gunshi-project-ss/src/main/java/com/gunshi/Tests.java

package com.gunshi;

import com.gunshi.project.ss.common.model.vo.OsmoticPressDetailVo;
import com.gunshi.project.ss.model.RegressionEquation;
import com.gunshi.project.ss.util.RegressionAnalysis;
import org.springframework.data.elasticsearch.client.elc.NativeQueryBuilder;

import java.math.BigDecimal;
import java.math.RoundingMode;
import java.text.SimpleDateFormat;
import java.time.format.DateTimeFormatter;
import java.util.*;

public class Tests extends Thread {

    public static SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

    public static DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");

    public static void main(String[] args) throws Exception {

    }

    class Myclass implements Cloneable{
        private String name;

        @Override
        public Object clone() throws CloneNotSupportedException {
            Myclass clone =  (Myclass) super.clone();
            return clone;
        }
    }


    /**
     * 根据回归方程计算y值
     * @param equation 回归方程字符串
     * @param x 自变量x的值
     * @return 计算得到的y值
     */
    private static BigDecimal calculateRegressionValue(String equation, BigDecimal x) {
        if (equation == null || equation.trim().isEmpty()) {
            return BigDecimal.ZERO;
        }

        // 清理方程字符串，移除空格和y=
        String cleanEquation = equation.replace("y =", "").replace(" ", "").toLowerCase();

        try {
            BigDecimal result;
            // 根据方程的形式判断阶数并计算
            if (cleanEquation.contains("x^4")) {
                result = calculateFourthOrder(cleanEquation, x);
            } else if (cleanEquation.contains("x^3")) {
                result = calculateThirdOrder(cleanEquation, x);
            } else if (cleanEquation.contains("x^2")) {
                result = calculateSecondOrder(cleanEquation, x);
            } else {
                result = calculateFirstOrder(cleanEquation, x);
            }
            // 四舍五入保留两位小数
            return result.setScale(2, RoundingMode.HALF_UP);
        } catch (Exception e) {
            // 计算异常时返回0
            return BigDecimal.ZERO;
        }
    }


    /**
     * 计算一阶线性方程 y = ax + b
     */
    private static BigDecimal calculateFirstOrder(String equation, BigDecimal x) {
        // 解析方程系数，格式如：0.0455x+94.2395
        String[] parts = equation.split("x");
        if (parts.length < 2) {
            return BigDecimal.ZERO;
        }

        BigDecimal a = parseCoefficient(parts[0]);
        BigDecimal b = parseCoefficient(parts[1]);

        return a.multiply(x).add(b);
    }

    /**
     * 计算二阶方程 y = ax^2 + bx + c
     */
    private static BigDecimal calculateSecondOrder(String equation, BigDecimal x) {
        // 解析方程系数，格式如：-68.4211x^2+16312.8684x-972224.1397
        String[] parts = equation.split("x");
        if (parts.length < 3) {
            return BigDecimal.ZERO;
        }

        BigDecimal a = parseCoefficient(parts[0]);
        BigDecimal b = parseCoefficient(parts[1].replace("^2", ""));
        BigDecimal c = parseCoefficient(parts[2]);

        BigDecimal x2 = x.multiply(x); // x^2
        return a.multiply(x2).add(b.multiply(x)).add(c);
    }

    /**
     * 计算三阶方程 y = ax^3 + bx^2 + cx + d
     */
    private static BigDecimal calculateThirdOrder(String equation, BigDecimal x) {
        // 解析方程系数，格式如：-2291.6667x^3+819497.9167x^2-97683901.8750x+3881297151.1650
        String[] parts = equation.split("x");
        if (parts.length < 4) {
            return BigDecimal.ZERO;
        }

        BigDecimal a = parseCoefficient(parts[0]);
        BigDecimal b = parseCoefficient(parts[1].replace("^3", "").replace("^2", ""));
        BigDecimal c = parseCoefficient(parts[2].replace("^2", ""));
        BigDecimal d = parseCoefficient(parts[3]);

        BigDecimal x2 = x.multiply(x); // x^2
        BigDecimal x3 = x2.multiply(x); // x^3

        return a.multiply(x3).add(b.multiply(x2)).add(c.multiply(x)).add(d);
    }

    /**
     * 计算四阶方程 y = ax^4 + bx^3 + cx^2 + dx + e
     */
    private static BigDecimal calculateFourthOrder(String equation, BigDecimal x) {
        // 解析方程系数，格式如：-5.9039x^4+523.5482x^3+316095.2736x^2-57676816.2672x+2688986002.6804
        String[] parts = equation.split("x");
        if (parts.length < 5) {
            return BigDecimal.ZERO;
        }

        BigDecimal a = parseCoefficient(parts[0]);
        BigDecimal b = parseCoefficient(parts[1].replace("^4", "").replace("^3", ""));
        BigDecimal c = parseCoefficient(parts[2].replace("^3", "").replace("^2", ""));
        BigDecimal d = parseCoefficient(parts[3].replace("^2", ""));
        BigDecimal e = parseCoefficient(parts[4]);

        BigDecimal x2 = x.multiply(x); // x^2
        BigDecimal x3 = x2.multiply(x); // x^3
        BigDecimal x4 = x3.multiply(x); // x^4

        return a.multiply(x4).add(b.multiply(x3)).add(c.multiply(x2)).add(d.multiply(x)).add(e);
    }

    /**
     * 解析系数，处理正负号和数字格式
     */
    private static BigDecimal parseCoefficient(String coeffStr) {
        if (coeffStr == null || coeffStr.isEmpty()) {
            return BigDecimal.ZERO;
        }

        // 处理空字符串情况
        if (coeffStr.equals("+") || coeffStr.equals("-")) {
            coeffStr += "1";
        }

        // 处理没有显式数字的情况，如：x^2+x+1 中的第一个x系数为1
        if (coeffStr.equals("")) {
            return BigDecimal.ONE;
        }

        try {
            return new BigDecimal(coeffStr);
        } catch (NumberFormatException e) {
            // 如果解析失败，尝试处理特殊情况
            if (coeffStr.equals("+")) {
                return BigDecimal.ONE;
            } else if (coeffStr.equals("-")) {
                return BigDecimal.ONE.negate();
            }
            return BigDecimal.ZERO;
        }
    }

}