磁异常.c

简单的计算地面磁异常的C程序

#include <stdio.h>
#include <math.h>
//#define x1 0.0
//#define y1 0.0
#define z1 300.0
#define L 100.0
#define pi 3.1415926
#define qm 1.0
double ZA(double q,double l,float alfa,double x,double y)
{
	double re,m,n,t,r;
	m=(q*(z1+l*sin(alfa)));
	n=(x-l*cos(alfa));
	t=(z1+l*sin(alfa));
	r=(n*n+y*y+t*t)*(n*n+y*y+t*t)*(n*n+y*y+t*t);
	re=(0.25/pi)*(m)/(sqrt(r));
	
	return re;
	
}
main()
{
	double x,y,an;
	float t,k,p;
	
	FILE *fp;
	fp=fopen("异常000.txt","w");
	printf("please input t\n");
	scanf("%f",&t);
	k=(t*pi)/180.0;
	p=cos(k);
	printf("%10.5f",p);
	y=0.0;
	for(x=-1000.0;x<=1000.0;x++)
	{
		an=ZA(-qm,L,(k),x,y)+ZA(qm,-L,(k),x,y);
		printf("%10.4f %30.20f\n",x,an);
		fprintf(fp,"%10.4f %30.20f\n",x,an);
	}
	fclose(fp);
}