h[d, f=3 in] := d^2/(4 f) g = new graphics g.line[0 in, 0 in, 9 in, 0 in] p=new polyline g.color[0.7,0.7,0.7] for d = 0 in to 9 in step .1 in { g.line[d, 0 in, d, h[d]] p.addPoint[d,h[d]] } g.color[0,0,0] g.add[p] // Draw line to focus g.line[0 in, 0 in, 0 in, 3 in] g.color[0,0,1,.5] g.fillRectCenter[0 in, 3 in, -.1 in, .1 in] //g.line[-1 in, 3 in, 1 in, 3 in] //g.show[] g.write["solar.svg", 10 in, 10 in, 1] //g.print[]