python绘制曲线

在翻看书本是一段曲线吸引了我，特别是这种三角函数正弦和余弦相交，让我体会到数学和python语言的魅力！

#绘制曲线
import numpy as np
import matplotlib.pyplot as plt
x1 = np.linspace(-2*np.pi,2*np.pi,50)
x2 = np.linspace(-4*np.pi,4*np.pi,50)
y1,y2 = np.sin(x1),np.cos(x2)
plt.plot(x1,y1,color='red',label='sin(x)')
plt.plot(x1,y2,color='blue',linestyle="-.",label='cos(x)')
plt.legend()
plt.savefig('./sincos.png')  
plt.show()