Python 进阶 (三十八) 利用 matplotlib 进行折线图，直方图和饼图的绘制

2022-11-15
江苏
本文字数：1785 字
阅读完需：约 6 分钟

一、前言

我用 10 个国家某年的 GDP 来绘图，数据如下：labels = ['USA', 'China', 'India', 'Japan', 'Germany', 'Russia', 'Brazil', 'UK', 'France', 'Italy']quants = [15094025.0, 11299967.0, 4457784.0, 4440376.0, 3099080.0, 2383402.0, 2293954.0, 2260803.0, 2217900.0, 1846950.0]

二、折线图绘制

首先绘制折线图，代码如下：

def draw_line(labels,quants):
    ind = np.linspace(0,9,10)
    fig = plt.figure(1)
    ax  = fig.add_subplot(111)
    ax.plot(ind,quants)
    ax.set_title('Top 10 GDP Countries', bbox={'facecolor':'0.8', 'pad':5})
    ax.set_xticklabels(labels)
    plt.grid(True)
plt.show()

复制代码

效果图如下图：

三、柱状图绘制

再画柱状图，代码如下：

def draw_bar(labels,quants):
    width = 0.4
    ind = np.linspace(0.5,9.5,10)
    # make a square figure
    fig = plt.figure(1)
    ax  = fig.add_subplot(111)
    # Bar Plot
    ax.bar(ind-width/2,quants,width,color='green')
    # Set the ticks on x-axis
    ax.set_xticks(ind)
    ax.set_xticklabels(labels)
    # labels
    ax.set_xlabel('Country')
    ax.set_ylabel('GDP (Billion US dollar)')
    # title
    ax.set_title('Top 10 GDP Countries', bbox={'facecolor':'0.8', 'pad':5})
    plt.grid(True)
plt.show()

复制代码

效果图如下图：

四、饼图绘制

最后画饼图，代码如下：

def draw_pie(labels,quants):
    plt.figure(1, figsize=(6,6))
    # For China, make the piece explode a bit
    expl = [0,0.1,0,0,0,0,0,0,0,0]
    # Colors used. Recycle if not enough.
    colors  = ["blue","red","coral","green","yellow","orange"]
    # autopct: format of "percent" string;
    plt.pie(quants, explode=expl, colors=colors, labels=labels, autopct='%1.1f%%',pctdistance=0.8, shadow=True)
    plt.title('Top 10 GDP Countries', bbox={'facecolor':'0.8', 'pad':5})
plt.show()

复制代码

效果图如下图：

五、完整代码

# -*- coding: gbk -*-
import numpy as np
import matplotlib.pyplot as plt
import matplotlib as mpl
 
def draw_pie(labels,quants):
    # make a square figure
    plt.figure(1, figsize=(6,6))
    # For China, make the piece explode a bit
    expl = [0,0.1,0,0,0,0,0,0,0,0]
    # Colors used. Recycle if not enough.
    colors  = ["blue","red","coral","green","yellow","orange"]
    # Pie Plot
    # autopct: format of "percent" string;
    plt.pie(quants, explode=expl, colors=colors, labels=labels, autopct='%1.1f%%',pctdistance=0.8, shadow=True)
    plt.title('Top 10 GDP Countries', bbox={'facecolor':'0.8', 'pad':5})
    plt.show()
def draw_bar(labels,quants):
    width = 0.4
    ind = np.linspace(0.5,9.5,10)
    # make a square figure
    fig = plt.figure(1)
    ax  = fig.add_subplot(111)
    # Bar Plot
    ax.bar(ind-width/2,quants,width,color='green')
    # Set the ticks on x-axis
    ax.set_xticks(ind)
    ax.set_xticklabels(labels)
    # labels
    ax.set_xlabel('Country')
    ax.set_ylabel('GDP (Billion US dollar)')
    # title
    ax.set_title('Top 10 GDP Countries', bbox={'facecolor':'0.8', 'pad':5})
    plt.grid(True)
    plt.show()
def draw_line(labels,quants):
    ind = np.linspace(0,9,10)
    fig = plt.figure(1)
    ax  = fig.add_subplot(111)
    ax.plot(ind,quants)
    ax.set_title('Top 10 GDP Countries', bbox={'facecolor':'0.8', 'pad':5})
    ax.set_xticklabels(labels)
    plt.grid(True)
    plt.show()
# quants: GDP
# labels: country name
labels   = ['USA', 'China', 'India', 'Japan', 'Germany', 'Russia', 'Brazil', 'UK', 'France', 'Italy']
quants   = [15094025.0, 11299967.0, 4457784.0, 4440376.0, 3099080.0, 2383402.0, 2293954.0, 2260803.0, 2217900.0, 1846950.0]
draw_pie(labels,quants)
#draw_bar(labels,quants)
#draw_line(labels,quants)