gpt4 book ai didi

c - 在C中,如何使用x
转载 作者:行者123 更新时间:2023-11-30 21:21:35 24 4
gpt4 key购买 nike

我有一个程序需要从文件中读取数据,但我不想给出文件名并希望将数据放入我的命令文件中,例如 nbody < input ???

我提供的代码(称为 nbody.c)是 N 体模拟的简化版本,它说明了上述理论。可以使用以下命令编译、链接代码并创建名为 nbody 的可执行文件。 gcc –lm nbody.c –o nbody

为了运行可执行文件,提供了一个名为 input 的示例数据输入文件作为起点。可以使用以下命令执行串行代码,该命令需要几秒钟才能运行完成。 nbody <输入

我的程序是;

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

int m = 1000;
void simulate(int m, int n, double delt, double eps, double x[], double y[], double z[],
int iter, double xn[], double yn[], double zn[]);

int main(int argc, char *argv[])
{
double x[m], y[m], z[m], xn[m], yn[m], zn[m];
double delt, eps, resultant;
int i, n, iter;

char ch, file_name[25];

FILE *fp, *ofp;
//file_name=argv[0];
//char *mode = "r";

printf("Enter the name of file you wish to see\n"); //instead of this, i wanted it reads automatically, like taking data from the file and calculate it.

gets(file_name);
fp = fopen(file_name, "r");

rewind(fp);
printf("The contents of %s file are : \n", file_name);

fscanf(fp,"%d %lf %lf", &n, &delt, &eps);
printf("n = %d, delta t = %lf and tolerance = %lf \n",n, delt, eps);

fclose(fp);

//while(ch=fgets(fp)!=EOF){

//printf("enter n, delta t and tolerance\n");
//scanf("%d %lf %lf", &n, &delt, &eps);
//printf("%c",ch)


//printf("enter n, delta t and tolerance\n");
//scanf("%d %lf %lf", &n, &delt, &eps);



simulate(m, n, delt, eps, x, y, z, iter, xn, yn, zn);
printf("n = %d, delta t = %lf and tolerance = %lf \n",n, delt, eps);
for (i=1; i <= n; i++) {
resultant = sqrt(x[i]*x[i]+y[i]*y[i]+z[i]*z[i]);
printf("%-5.7lf %-5.7lf %-5.7lf %-5.7lf\n", x[i], y[i], z[i], resultant);
}
return 0;
}


void simulate(int m, int n, double delt, double eps, double x[], double y[], double z[],
int iter, double xn[], double yn[], double zn[])
{
/*
Author C.Ierotheou
Aug 2009
Copyright University of Greenwich
routine to crudely simulate body-body interactions (inefficient method)
*/
double zero = 0.0, one = 1.0, twopi = 6.2831853071795864769252866;
int i, itest, j;
double aux,auy,delt2,delt3,eps2,fx,fy,fz,ftx,fty,ftz,step;

// return if n<5
if (n < 5) return;

//initialization
iter = 0;
delt2 = 0.5*delt*delt;
delt3 = delt2*delt2;
eps2 = eps*eps;

//initial distribution of points
auy = zero;
itest=n+1;
j = n+2;
fx = (double)(n);
x[1] = zero;
y[1] = zero;
z[1] = one;
for (i=2; i <= n; i++) {
step = (double)(i+i-j)/fx;
auy = fmod(auy+3.6/sqrt(itest*(one-step*step)),twopi);
aux = sin(auy);
x[i] = aux*step;
y[i] = aux*sin(acos(step));
z[i] = cos(auy);
}

// main iteration loop

Mainloop:
iter=iter+1;
itest=0;
for (i=1; i <= n; i++) {
// total sum of force vectors
fx=zero;
fy=zero;
fz=zero;
for (j=1; j<=n ; j++) {
if (j != i) {
aux=pow(x[i]-x[j],2.0)+pow(y[i]-y[j],2.0)+pow(z[i]-z[j],2.0);
aux=aux*sqrt(aux);
fx=fx+(x[i]-x[j])/aux;
fy=fy+(y[i]-y[j])/aux;
fz=fz+(z[i]-z[j])/aux;
}
}
// tangential component of force
aux=x[i]*fx+y[i]*fy+z[i]*fz;
ftx=fx-x[i]*aux;
fty=fy-y[i]*aux;
ftz=fz-z[i]*aux;
aux=ftx*ftx+fty*fty+ftz*ftz;
if (aux > eps2) {
itest=1;
aux=sqrt(one-aux*delt3);
xn[i]=x[i]*aux+ftx*delt2;
yn[i]=y[i]*aux+fty*delt2;
zn[i]=z[i]*aux+ftz*delt2;
}
}
for (i=1; i <= n; i++) {
x[i]=xn[i];
y[i]=yn[i];
z[i]=zn[i];
}
if (itest == 1) goto Mainloop;
}

最佳答案

你问:

In C, how to read data from file using x

您不会在 C 中执行此操作。这种功能由您的 shell/控制台/运行时环境提供。

如果您有一个程序x,可以从stdin读取其输入,并且您有一个文件y,其中包含适用于x,您使用:

x < y

来自外壳。

更新

我想我知道你的问题可能出在哪里。你有:

char ch, file_name[25];

FILE *fp, *ofp;
//file_name=argv[0];
//char *mode = "r";

printf("Enter the name of file you wish to see\n"); //instead of this, i wanted it reads automatically, like taking data from the file and calculate it.

gets(file_name);
fp = fopen(file_name, "r");

您希望从命令行传递输入文件的名称,而不是使用 gets 读取输入文件的名称。我希望我在这方面走在正确的道路上。

在这种情况下,您需要使用:

char* file_name = argv[1]; // argv[0] is the program name
// argv[1] is the first argument to the program

然后,您可以使用:

x y

其中x是您的程序,y包含x所需的输入数据。

关于c - 在C中,如何使用x<y(y是文件名)从文件中读取数据,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/24457742/

24 4 0

Copyright 2021 - 2024 cfsdn All Rights Reserved 蜀ICP备2022000587号
广告合作:1813099741@qq.com 6ren.com