def ex65():
screenx = 400
screeny = 400
canvas = Canvas(width=screenx, height=screeny, bg='white')
AspectRatio = 0.85
MAXPTS = 15
h = screeny
w = screenx
xcenter = w / 2
ycenter = h / 2
radius = (h - 30) / (AspectRatio * 2) - 20
step = 360 / MAXPTS
angle = 0.0
for i in range(MAXPTS):
rads = angle * math.pi / 180.0
p = PTS()
p.x = xcenter + int(math.cos(rads) * radius)
p.y = ycenter - int(math.sin(rads) * radius * AspectRatio)
angle += step
points.append(p)
canvas.create_oval(xcenter - radius, ycenter - radius,
xcenter + radius, ycenter + radius)
for i in range(MAXPTS):
for j in range(i, MAXPTS):
canvas.create_line(points[i].x, points[i].y, points[j].x, points[j].y)
canvas.pack()
mainloop()
def ex57():
canvas = Canvas(width=300, height=300, bg='green')
canvas.pack(expand=YES, fill=BOTH)
x0 = y0 = 263
x1 = y1 = 275
for i in range(19):
canvas.create_line(x0, y0, x0, y1, width=1, fill='red')
x0 -= 5
y0 -= 5
x1 += 5
y1 += 5
x0 = y0 = 263
y1 = 275
for i in range(21):
canvas.create_line(x0, y0, x0, y1, fill='red')
x0 += 5
y0 += 5
y1 += 5
mainloop()
def ex59():
canvas = Canvas(width=300, height=300, bg='green')
canvas.pack(expand=YES, fill=BOTH)
x0 = 150
y0 = 100
canvas.create_oval(x0 - 10, y0 - 10, x0 + 10, y0 + 10)
canvas.create_oval(x0 - 20, y0 - 20, x0 + 20, y0 + 20)
canvas.create_oval(x0 - 50, y0 - 50, x0 + 50, y0 + 50)
B = 0.809
for i in range(16):
a = 2 * math.pi / 16 * i
x = math.ceil(x0 + 48 * math.cos(a))
y = math.ceil(y0 + 48 * math.sin(a) * B)
canvas.create_line(x0, y0, x, y, fill='red')
canvas.create_oval(x0 - 60, y0 - 60, x0 + 60, y0 + 60)
for k in range(501):
for i in range(17):
a = (2 * math.pi / 16) * i + (2 * math.pi / 180) * k
x = math.ceil(x0 + 48 * math.cos(a))
y = math.ceil(y0 + 48 + math.sin(a) * B)
canvas.create_line(x0, y0, x, y, fill='red')
for j in range(51):
a = (2 * math.pi / 16) * i + (2 * math.pi / 180) * k - 1
x = math.ceil(x0 + 48 * math.cos(a))
y = math.ceil(y0 + 48 * math.sin(a) * B)
canvas.create_line(x0, y0, x, y, fill='red')
mainloop()