Python画正态曲线、太极图案

源码：

import numpy as np
import matplotlib.pyplot as plt
import math


def normal_distribution(x, mean, sigma):
    return np.exp(-1 * ((x - mean) ** 2) / (2 * (sigma ** 2))) / (math.sqrt(2 * np.pi) * sigma)


mean1, sigma1 = 0, 1
x1 = np.linspace(mean1 - 6 * sigma1, mean1 + 6 * sigma1, 100)

mean2, sigma2 = 0, 2
x2 = np.linspace(mean2 - 6 * sigma2, mean2 + 6 * sigma2, 100)

mean3, sigma3 = 5, 1
x3 = np.linspace(mean3 - 6 * sigma3, mean3 + 6 * sigma3, 100)

y1 = normal_distribution(x1, mean1, sigma1)
y2 = normal_distribution(x2, mean2, sigma2)
y3 = normal_distribution(x3, mean3, sigma3)

plt.plot(x1, y1, 'r', label='m=0,sig=1')
plt.plot(x2, y2, 'g', label='m=0,sig=2')
plt.plot(x3, y3, 'b', label='m=1,sig=1')
plt.legend()
plt.grid()
plt.show()

效果图：

源码：

import turtle

# 定义大圆半径200,则小圆半径big_radius * 0.5, 假如内部最小圆半径为big_radius*0.15
big_radius = 200


def main():
    turtle.reset()
    turtle.shape("turtle")
    yin("black", "white", 1)
    yin("white", "black", -1)
    turtle.ht()


def yin(big_fillcolor, inner_fillcolor, direction):
    """
    画一半阴阳八卦
    :param big_fillcolor:   外部大圆填充色
    :param inner_fillcolor: 内部小圆填充色
    :param direction: 1表示开始默认开始方向向右,-1表示开始默认开始方向向左
    :return:
    """
    turtle.pensize(3)
    # 设置pencolor和fillcolor
    turtle.color("black", big_fillcolor)
    # 开始填充
    turtle.begin_fill()
    # 画内半圆
    turtle.circle(big_radius / 2.0, 180)
    # 画外半圆
    turtle.circle(big_radius, 180)
    # 海龟箭头左转180度
    turtle.lt(180)
    # 反方向画内半圆,反方向画圆,半径前要加 -
    turtle.circle(-big_radius / 2.0, 180)
    # 结束填充
    turtle.end_fill()
    # 画笔抬起
    turtle.pu()
    # 从画笔当前位置开始画圆,因此需要减去内圆半径,y方向移动,x方向不变
    turtle.sety(direction * big_radius * (0.5 - 0.15))
    # 画笔放下
    turtle.pd()
    # 设置pencolor和fillcolor
    turtle.color(big_fillcolor, inner_fillcolor)
    # 开始填充内圆
    turtle.begin_fill()
    # 画内圆
    turtle.circle(big_radius * 0.15)
    # 结束填充内圆
    turtle.end_fill()
    # 画笔抬起
    turtle.pu()
    # 海龟箭头回到(0, 0)坐标
    turtle.goto(0, 0)
    # 画笔放下
    turtle.pd()
    # 海龟箭头左转180度
    turtle.lt(180)
    return "Done!"


if __name__ == '__main__':
    main()
    turtle.mainloop()

效果图：