参考链接： Python中的numpy.log10
对数函数
import math
import matplotlib.pyplot as plt
import numpy as np
if __name__ == '__main__':
x = np.arange(0.05,3,0.05)
y1 = [math.log(a,1.5) for a in x]
plt.plot(x,y1,linewidth=2,color='red',label ='log1.5(x)')
print(y1)
plt.plot([1,1],[y1[0],y1[-1]],"r--",linewidth=2)
y2 = [math.log(a, 2) for a in x]
plt.plot(x, y2, linewidth=2, color='green', label='log2(x)')
y3 = [math.log(a, 3) for a in x]
plt.plot(x, y3, linewidth=2, color='blue', label='log3(x)')
plt.legend(loc='lower right')
plt.grid(True)
plt.show()
如果a的x次方=N（a>0，且a≠1），
那么数x叫做以a为底N的对数，记作x=logaN，读作以a为底N的对数，其中a叫做对数的底数，N叫做真数
