draw a line for tracking the object

CvSeq* circles = cvHoughCircles( gray, cvCreateMemStorage(0), CV_HOUGH_GRADIENT, 2 , gray->height/6, 3 );
printf ("%d circles detected\n", circles->total);
int *px = new int[circles->total];
int *py = new int[circles->total];
if(circles->total > 0) {
int i = 0;
float * p = (float*)cvGetSeqElem( circles, i );
int i=0;
px[i]=cvRound(p[0]);
py[i]=cvRound(p[1]);
int radius = cvRound(p[2]);
int measurement[] = { px[i], py[i] };