// this method will draw an arrow drawarrow(int x1,int y1,int x2,int y2)
void drawArrowLine(Graphics g, int i, int j, int k, int l)
{
double d = Math.sqrt((k - i) * (k - i) + (l - j) * (l - j));
double d1 = (double)(-(k - i)) / (double)(l - j);
double d2 = 6D / Math.sqrt(1.0D + d1 * d1);
double d3 = 6D / Math.sqrt(1.0D + 1.0D / d1 / d1);
if(d1 < 0.0D)
d3 = -d3;
double d4 = (double)k - (double)(10 * (k - i)) / d;
double d5 = (double)l - (double)(10 * (l - j)) / d;
g.drawLine(i, j, (int)d4, (int)d5);
int ai[] = {
(int)(d4 - d2), k, (int)(d4 + d2)
};
int ai1[] = {
(int)(d5 - d3), l, (int)(d5 + d3)
};
g.fillPolygon(ai, ai1, 3);
}