java案例统计斜长传精准度如何？

wen java案例 2026-11-15 1

Java 案例：统计斜长传精准度

下面我用一个完整的 Java 案例来演示如何统计足球比赛中斜长传（Diagonal Long Pass）的精准度，核心思路是：定义传球事件、判定斜长传、判定是否精准、汇总统计。

java案例统计斜长传精准度如何？

数据模型

import java.util.*;
import java.util.stream.*;
/**
 * 传球事件
 */
class PassEvent {
    private String playerName;      // 传球球员
    private double startX, startY;  // 起点坐标（球场 105x68，原点左下角）
    private double endX, endY;      // 终点坐标
    private boolean reachedTeammate; // 是否被队友接到（未被断/未出界）
    private String receiverTeam;    // 接球方队伍（用于判定是否队友）
    public PassEvent(String playerName, double startX, double startY,
                     double endX, double endY,
                     boolean reachedTeammate, String receiverTeam) {
        this.playerName = playerName;
        this.startX = startX;
        this.startY = startY;
        this.endX = endX;
        this.endY = endY;
        this.reachedTeammate = reachedTeammate;
        this.receiverTeam = receiverTeam;
    }
    // getter
    public String getPlayerName() { return playerName; }
    public double getStartX() { return startX; }
    public double getStartY() { return startY; }
    public double getEndX() { return endX; }
    public double getEndY() { return endY; }
    public boolean isReachedTeammate() { return reachedTeammate; }
    public String getReceiverTeam() { return receiverTeam; }
    /** 传球距离（米） */
    public double getDistance() {
        return Math.hypot(endX - startX, endY - startY);
    }
    /** 传球方向与场地横向(x轴)的夹角（度） */
    public double getAngleToXAxis() {
        return Math.toDegrees(Math.atan2(endY - startY, endX - startX));
    }
}

斜长传判定 + 精准度统计

class PassAnalyzer {
    /** 长传阈值：>=25 米 */
    private static final double LONG_PASS_MIN_DISTANCE = 25.0;
    /** 斜传判定：与 x 轴夹角在 [30°, 150°] 之间（即明显带纵向分量） */
    private static final double MIN_ANGLE = 30.0;
    private static final double MAX_ANGLE = 150.0;
    /**
     * 判断是否为斜长传
     */
    public static boolean isDiagonalLongPass(PassEvent p) {
        double dist = p.getDistance();
        double angle = Math.abs(p.getAngleToXAxis());
        // 归一到 [0,180]
        if (angle > 180) angle = 360 - angle;
        boolean isLong = dist >= LONG_PASS_MIN_DISTANCE;
        boolean isDiagonal = angle >= MIN_ANGLE && angle <= MAX_ANGLE;
        return isLong && isDiagonal;
    }
    /**
     * 统计某球员斜长传精准度
     * 精准定义：球被本方队友接到
     */
    public static void printPlayerStats(List<PassEvent> allPasses, String teamName) {
        Map<String, List<PassEvent>> byPlayer = allPasses.stream()
            .filter(PassAnalyzer::isDiagonalLongPass)
            .collect(Collectors.groupingBy(PassEvent::getPlayerName));
        System.out.printf("%-10s %6s %6s %8s%n",
                "球员", "总数", "成功", "精准度");
        System.out.println("-------------------------------------");
        byPlayer.forEach((name, list) -> {
            long total = list.size();
            long success = list.stream()
                    .filter(p -> p.isReachedTeammate()
                              && teamName.equals(p.getReceiverTeam()))
                    .count();
            double accuracy = total == 0 ? 0 : success * 100.0 / total;
            System.out.printf("%-10s %6d %6d %7.2f%%%n",
                    name, total, success, accuracy);
        });
    }
    /**
     * 统计全队总体斜长传精准度
     */
    public static double teamAccuracy(List<PassEvent> allPasses, String teamName) {
        List<PassEvent> diag = allPasses.stream()
                .filter(PassAnalyzer::isDiagonalLongPass)
                .collect(Collectors.toList());
        long total = diag.size();
        long success = diag.stream()
                .filter(p -> p.isReachedTeammate() && teamName.equals(p.getReceiverTeam()))
                .count();
        return total == 0 ? 0 : success * 100.0 / total;
    }
}

测试用例

public class DiagonalPassDemo {
    public static void main(String[] args) {
        List<PassEvent> passes = new ArrayList<>();
        // 球员A：3次斜长传，2次成功
        passes.add(new PassEvent("A", 30, 20, 60, 50, true,  "Home")); // 斜长传 ✔
        passes.add(new PassEvent("A", 20, 10, 55, 45, true,  "Home")); // 斜长传 ✔
        passes.add(new PassEvent("A", 40, 30, 70, 10, false, "Away")); // 斜长传，失败
        // 球员B：2次斜长传，1次成功
        passes.add(new PassEvent("B", 50, 55, 80, 25, true,  "Home")); // 斜长传 ✔
        passes.add(new PassEvent("B", 10, 60, 40, 30, false, "Away")); // 斜长传 ✘
        // 干扰项：直长传（角度接近0），不算斜长传
        passes.add(new PassEvent("C", 20, 34, 60, 34, true, "Home"));
        // 干扰项：短斜传（距离<25），不算
        passes.add(new PassEvent("C", 30, 30, 40, 40, true, "Home"));
        PassAnalyzer.printPlayerStats(passes, "Home");
        System.out.println("-------------------------------------");
        System.out.printf("全队斜长传精准度：%.2f%%%n",
                PassAnalyzer.teamAccuracy(passes, "Home"));
    }
}

输出结果

球员             总数   成功    精准度
-------------------------------------
A                 3      2   66.67%
B                 2      1   50.00%
-------------------------------------
全队斜长传精准度：60.00%

关键设计点说明

环节	说明
斜长传定义	距离 ≥ 25m 且与 x 轴夹角在 30°~150°（保留横向推进又带纵向变化）
精准判定	优先看 `reachedTeammate`；进一步验证 `receiverTeam == 本方`，避免把“对方解围后本方捡到”算成功
角度归一化	`atan2` 会返回负角度，需要 `Math.abs` 或 `360-angle` 处理，避免方向判断遗漏
球场地坐标	采用 105×68 米真实球场尺度，便于把像素坐标换算
可扩展	`isDiagonalLongPass` 中的阈值可配置；如需按“传向进攻三区”进一步筛选，只需再加禁区判定