python数学库01

import math
import matplotlib.pyplot as plt

_name_ = '__main__'

if _name_ == "__main__":
    x = [float(i) / 100 for i in range(1, 300)]
    y = [math.log(i) for i in x]
    plt.plot(x, y, "r-", linewidth=3, label="log Curve")
    a = [x[20], x[175]]
    b = [y[20], y[175]]
    plt.plot(a, b, "g-", linewidth=2)
    plt.plot(a, b, "b", markersize=15, alpha=0.75)
    plt.legend(loc="upper left")
    plt.grid(True)
    plt.xlabel("x")
    plt.ylabel("log(x)")
    plt.show()

运行结果

 

import numpy
import matplotlib.pyplot as plt

__name__ = "__main__"

if __name__ == "__main__":
    u = numpy.random.uniform(0.0, 1.0, 10000)
    plt.hist(u, 80, facecolor="g", alpha=0.75)
    plt.grid(True)
    plt.show()

    times = 10000
    for time in range(times):
        u += numpy.random.uniform(0.0, 1.0, 10000)
    print(len(u))
    u /= times
    print(len(u))
    plt.hist(u, 80, facecolor="g", alpha=0.75)
    plt.grid(True)
    plt.show()

运行结果