wajs

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

double X(double t) {
	return(1.0*sin(2.0*M_PI*10000.0*t)*cos(2.0*M_PI*20000.0*t));
}

struct complexx {
	double Re;
	double Im;
};
struct complexx cmplx(double A, double B) {
	struct complexx result;
	result.Re=A;
	result.Im=B;
	return(result);
}
struct complexx cMult(struct complexx A, struct complexx B) {
	struct complexx result;
	result.Re=A.Re*B.Re-A.Im*B.Im;
	result.Im=A.Re*B.Im+A.Im*B.Re;
	return(result);
}
struct complexx cDiv(struct complexx nr, struct complexx d) {
	double btm, re_top, im_top;
	struct complexx result;
	btm=d.Re*d.Re+d.Im*d.Im;
	re_top=nr.Re*d.Re+nr.Im*d.Im;
	im_top=nr.Im*d.Re-nr.Re*d.Im;
	result.Re=re_top/btm;
	result.Im=im_top/btm;
	return(result);
}
struct complexx cAdd(struct complexx A, struct complexx B) {
	struct complexx result;
	result.Re=A.Re+B.Re;
	result.Im=A.Im+B.Im;
	return(result);
}
int main(void) {
	//clrscr();
	double x[8];
	struct complexx z[8];
	int N=8;
	int n,m;
	struct complexx sXz=cmplx((double)0.0, (double)0.0);
	double re,im;
	double h,fs;
	fs=80000;
	h=1.0/fs;
	double sX;
	double sY;
	double XX[8],YY[8];
	for(m=0;m<N;m=m+1) {
		sX=0.0;
		sY=0.0;
		for(n=0;n<N;n=n+1) {
			sX=sX+X(n*h)*cos(2.0*M_PI*(double)n*(double)m/(double)N);
			sY=sY-X(n*h)*sin(2.0*M_PI*(double)n*(double)m/(double)N);
		}
		XX[m]=sX;
		YY[m]=sY;
		printf("\n DFT X(%d)=%12.4f",m,*(XX+m));
		printf("       Y(%d)=%12.4f",m,*(YY+m));
	}
	for(n=0;n<N;n=n+1) {
		sXz=cmplx(0.0, 0.0);
		for(m=0;m<N;m=m+1) {
		sXz=cAdd(sXz,cMult(cmplx(XX[m],YY[m]),cmplx(cos(2.0*M_PI*n*m/N),sin(2.0*M_PI*n*m/N))));

		}
		printf("\n IDFT");
		printf(" x(%d) %12.4f ",n,cDiv(sXz,cmplx(N,0.0)));
	}
	printf("\n probki sygnalu");
	for(n=0;n<N;n=n+1) printf("\n   x[%d]=%12.4f ",n,X(n/fs));
    int abc;
    scanf("%d", &abc);
	}