wavy circle by equation

/* For cartesian coordinate system, enter parametric equation
/* in terms of t (which will vary from 0 to 1) for x, y and z
/* For example: for a circle in x-y plane, centered at origin
/* and radius = 4, the parametric equations will be:
/* x = 4 * cos ( t * 360 )
/* y = 4 * sin ( t * 360 )
/* z = 0
/*-------------------------------------------------------------------
r = 50
a = 5
n = 20

x = (r + a * sin(n * t * 360 )) * cos (t * 360 )
y = (r + a * sin(n * t * 360 )) * sin (t * 360 )