int main(int argc, char *argv[])
{
const char *space_file = "space.txt"; // 書き出すファイル
double dt = 1.0; // 時刻の刻み幅
const double stop_time = 400; // 実行時間
FILE *fp;
int c; // オプション指定
int i;
double t = 0;
if ((fp = fopen(space_file, "w")) == NULL) {
fprintf(stderr, "error: cannot open %s.\n", space_file);
return 1;
}
// コマンドライン引数の読み込み
for (i = 0; i < argc; i++) {
if (strcmp(argv[i], "-d") == 0) {
if (i + 1 < argc)
dt = atof(argv[i + 1]); // 刻み幅
}
}
// 繰り返し
for (i = 0; t <= stop_time; i++, t += dt) {
update_velocities(dt);
update_positions(dt);
if (i % 10 == 0) {
plot_stars(fp, t);
}
}
fclose(fp);
}
int main(int argc, char *argv[])
{
const char *space_file = "space.txt";
FILE *fp;
if ((fp = fopen(space_file, "w")) == NULL) {
fprintf(stderr, "error: cannot open %s.\n", space_file);
return 1;
}
double dt;
const double stop_time = 400;
int c;
while((c = getopt(argc,argv,"t:h")) != -1){
switch(c){
case 't':
dt = atof(optarg);
break;
case 'h':
printf ("enter dt\n");
break;
}
}
int i;
double t = 0;
for (i = 0; t <= stop_time; i++, t += dt) {
update_velocities(dt);
update_positions(dt);
if (i % 10 == 0) {
plot_stars(fp, t);
}
}
fclose(fp);
}
int main()
{
const char *space_file = "space.txt";
FILE *fp;
if ((fp = fopen(space_file, "w")) == NULL) {
fprintf(stderr, "error: cannot open %s.\n", space_file);
return 1;
}
const double dt = 1.0;
const double stop_time = 400;
int i;
double t = 0;
for (i = 0; t <= stop_time; i++, t += dt) {
update_velocities(dt);
update_positions(dt);
if (i % 10 == 0) {
plot_stars(fp, t);
}
}
fclose(fp);
}