/*  cartoid plots  */
/*  time-consuming quantity of plot-points */
load('draw)$
draw2d(proportional_axes = 'xy, dimensions=[1024, 768],
  yrange=[-17, 12], nticks=150,
  parametric(16*sin(x)^3, 13*cos(x)-5*cos(2*x)-2*cos(3*x)-cos(4*x), x, 0, 2*%pi)
);