如何制作蟒龟的余弦波形图？

import turtle
import math

# 创建画布和画笔
canvas = turtle.Screen()
canvas.title("蟒龟的余弦波形图")
canvas.bgcolor("white")
pen = turtle.Turtle()
pen.speed(0)
pen.color("blue")
pen.penup()

# 设置起始位置
x = -240
y = 0
pen.goto(x, y)
pen.pendown()

# 绘制余弦波形
amplitude = 100  # 振幅
frequency = 0.02  # 频率
x_increment = 1  # x轴每次增加的距离

while x < 240:
    y = amplitude * math.cos(frequency * x)
    pen.goto(x, y)
    x += x_increment

# 关闭画布
canvas.exitonclick()