C言語で距離を計算する！基礎から学ぶdist関数の完全ガイド10ステップ

#include <stdio.h>
#include <math.h>

double dist(double x1, double y1, double x2, double y2) {
    double dx = x2 - x1;
    double dy = y2 - y1;
    return sqrt(dx * dx + dy * dy);
}

int main() {
    double distance = dist(1.0, 2.0, 4.0, 6.0);
    printf("距離は%fです\n", distance);
    return 0;
}

#include <stdio.h>
#include <math.h>

double dist3D(double x1, double y1, double z1, double x2, double y2, double z2) {
    double dx = x2 - x1;
    double dy = y2 - y1;
    double dz = z2 - z1;
    return sqrt(dx * dx + dy * dy + dz * dz);
}

int main() {
    double distance = dist3D(1.0, 2.0, 3.0, 4.0, 5.0, 6.0);
    printf("距離は%fです\n", distance);
    return 0;
}

#include <stdio.h>
#include <math.h>

double dist(double x1, double y1, double x2, double y2) {
    double dx = x2 - x1;
    double dy = y2 - y1;
    return sqrt(dx * dx + dy * dy);
}

int main()

 {
    double points[4][2] = {{1.0, 2.0}, {4.0, 6.0}, {7.0, 8.0}, {10.0, 12.0}};
    for (int i = 0; i < 3; i++) {
        double distance = dist(points[i][0], points[i][1], points[i+1][0], points[i+1][1]);
        printf("%d番目と%d番目の点との距離は%fです\n", i+1, i+2, distance);
    }
    return 0;
}

1番目と2番目の点との距離は5.000000です
2番目と3番目の点との距離は3.605551です
3番目と4番目の点との距離は5.000000です

#include <stdio.h>
#include <math.h>

#define EARTH_RADIUS 6371.0

double deg2rad(double deg) {
    return deg * (M_PI/180);
}

double distOnEarth(double lat1, double lon1, double lat2, double lon2) {
    lat1 = deg2rad(lat1);
    lon1 = deg2rad(lon1);
    lat2 = deg2rad(lat2);
    lon2 = deg2rad(lon2);

    double dlon = lon2 - lon1;
    double dlat = lat2 - lat1;
    double a = sin(dlat/2) * sin(dlat/2) + cos(lat1) * cos(lat2) * sin(dlon/2) * sin(dlon/2);
    double c = 2 * atan2(sqrt(a), sqrt(1-a));
    return EARTH_RADIUS * c;
}

int main() {
    double distance = distOnEarth(35.6895, 139.6917, 34.6937, 135.5023); // Tokyo to Osaka
    printf("距離は%f kmです\n", distance);
    return 0;
}

#include <stdio.h>
#include <math.h>

double dist(double x1, double y1, double x2, double y2) {
    double dx = x2 - x1;
    double dy = y2 - y

1;
    return sqrt(dx*dx + dy*dy);
}

int classify(double point[2], double training_set[4][3]) {
    double min_distance = dist(point[0], point[1], training_set[0][0], training_set[0][1]);
    int min_index = 0;
    for (int i = 1; i < 4; i++) {
        double distance = dist(point[0], point[1], training_set[i][0], training_set[i][1]);
        if (distance < min_distance) {
            min_distance = distance;
            min_index = i;
        }
    }
    return training_set[min_index][2];
}

int main() {
    double training_set[4][3] = {{1.0, 2.0, 0}, {4.0, 6.0, 0}, {7.0, 8.0, 1}, {10.0, 12.0, 1}};
    double point[2] = {5.0, 5.0};

    int class = classify(point, training_set);
    printf("分類結果は%dです\n", class);
    return 0;
}

#include <stdio.h>
#include <math.h>

double manhattanDist(double x1, double y1, double x2, double y2) {
    return fabs(x2 - x1) + fabs(y2 - y1);
}

int main() {
    double distance = manhattanDist(1.0, 2.0, 4.0, 6.0);
    printf("マンハッタン距離は%fです\n", distance);
    return 0;
}

#include <stdio.h>
#include <math.h>

double vectorDist(double v1[3], double v2[3]) {
    double dx = v2[0] - v1[0];
    double dy = v2[1] - v1[1];
    double dz = v2[2] - v

1[2];
    return sqrt(dx*dx + dy*dy + dz*dz);
}

int main() {
    double v1[3] = {1.0, 2.0, 3.0};
    double v2[3] = {4.0, 5.0, 6.0};
    double distance = vectorDist(v1, v2);
    printf("ベクトル間の距離は%fです\n", distance);
    return 0;
}