text.moveTo(x_to_client(synthesis_xs[min_i]), y_to_client(synthesis_ys[min_i]));
        synthesis_context.lineTo(client_x, client_y);
        synthesis_context.strokeStyle="#AA3311";
        synthesis_context.stroke();
        synthesis_context.closePath();
        synthesis_context.setLineDash([]);
    }
}


// Runge
var runge_xs = [-1.0, 0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0];
var runge_ys = [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 5.0, 4.0, 3.0, 2.0, 1.0];
var runge_n = 11;
var runge_i = 0;

function 