```source("http://macosa.dima.unige.it/r.R")
# vedi qui (cerca "curva" e poi vai su "di Bezier")
PLANE(-3,3,-3,3)
x1 = c(-3,-1,1,3,3)
y1 = c(0,-2,2,0,-2)
bezier(x1,y1,3)
bezier(x1,y1,0)

PLANE(-4,4,-4,4)
a = c(-3,2,2,-1)
b = c(2,1,-3,4)
bezier(a,b,2)
bezier(a,b,0)

PLANE(-3,3,-3,3)
x2 = c(-1, -2,- 3,- 3,-2, -1, 0,  1, 2, 3, 3,  2, 1)
y2 = c(-2,-1.5,-1, 1, 2, 2.5,2.6,2.5,2, 1,-1,-1.5,-2)
bezier(x2,y2,0)
x3 = c(0,1,2,3,2, 0, -2,-3,-2, 0, 2,3,2, 0, -2,-3,-2,-1,0)
y3 = c(-4,-4,-2,-1,-1/2,0,1/2,1,2,4,2,1,1/2,0,-1/2,-1,-2,-4,-4)
PLANE(-4,4,-4,4)
bezier(x3,y3,0)

xx = c(-1,-1,0,0,1,1)
yy = c(0,1,1,-1,-1,0)
PLANE(-1,1,-1,1)
bezier(xx,yy,0); bezier(xx,-yy,0)

xx = c(   0,  -1, -3, -4,  -4, -3, -1,  0,   1,  3,   4,  4,  3,  1,    0)
yy = c(5.16,5.16,2.4,1.2,.012,.06,.24,21.6,.24,.06,.012,1.2,2.4,5.16,5.16)
xxx = c( -2, -2,  0,   2,  2)
yyy = c(3.1,-3.1,3.1,-3.1,3.1)
xxxx = c(-0.5,-0.5,0,0.5,0.5)
yyyy = c(  0,  3.5,0,3.5, 0)
PLANE(-3,3, 0,6)
bezier(xxx,yyy,1); bezier(xxxx,yyyy,"brown"); bezier(xx,yy,"red")

```