量化投资与Python——Matplotlib
简介
案例
案例一：常用函数
import matplotlib.pyplot as plt import numpy as np plt.rcParams['font.sans-serif'] = ['SimHei'] # 用来正常显示中文标签 plt.rcParams['axes.unicode_minus'] = False # 用来正常显示负号 x = np.linspace(-5, 5, 20) y1 = x y2 = x ** 2 y3 = 3 * x ** 3 + 5 * x ** 2 + 2 * x + 1 plt.plot(x, y1, 'h-r', label='y=x') plt.plot(x, y2, '*-c', label='y=x**2') plt.plot(x, y3, label='y=3x**3+5x**2+2x+1') plt.title('折线图') plt.xlabel('x轴') plt.ylabel('y轴') # plt.xlim(0, 10) # x轴的范围 # plt.ylim(0, 10) # x轴的范围 # plt.xticks(np.arange(0, 10, 3)) # 刻度、步长 # plt.yticks(np.arange(0, 10, 3)) # 刻度、步长 plt.legend() # 设置曲线图例说明 plt.show()
案例二：画布
x = np.linspace(-5, 5, 20) y1 = x y2 = x ** 2 y3 = 3 * x ** 3 + 5 * x ** 2 + 2 * x + 1 fig = plt.figure() ax1 = fig.add_subplot(2, 2, 1) ax1.plot(x, y2, 'o-r') fig.show() ax2 = fig.add_subplot(2, 2, 2) ax2.plot(x, y1, 'o-r', label='y=x') fig.show() ax3 = fig.add_subplot(2, 2, 3) ax3.plot(x, y3, 'o-r', label='y=x') fig.show()
案例四：柱状图与饼状图
# 柱状图 data = [5, 8, 13, 21] label = ['a', 'b', 'c', 'd'] plt.bar(np.arange(len(data)), data, align='center', color='red', width=0.3) # 默认 align='center' width=0.8 plt.xticks(np.arange(len(data)), labels=label) plt.show() # 饼状图 data = [5, 8, 13, 21] label = ['a', 'b', 'c', 'd'] plt.pie(data,labels=label,autopct='%.2f%%',explode=[0,0,0.1,0])# .2 表示保留两位小数 # plt.axis('equal') # 是图竖起来 plt.show()
案例五：绘制K线图
# mpl_finance 中有许多绘制金融相关的函数接口 # 绘制K线图：mpl_finance.candlestick_ochl 函数 import mpl_finance as fin import pandas as pd from matplotlib.dates import date2num df = pd.read_csv('./601318.csv', parse_dates=['date'], index_col=['date'])[['open', 'close', 'high', 'low']] df['time'] = date2num(df.index.to_pydatetime()) fig = plt.figure() ax = fig.add_subplot(1, 1, 1) arr = df[['time', 'open', 'close', 'high', 'low']].values fin.candlestick_ochl(ax, arr) plt.grid() fig.show()
