第九章 深度學習 python經典習題 條形圖 正弦函數 散點圖 表格排序（類似結構體）

題目

import matplotlib.pyplot as plt
name_list = ['1', '2', '3', '4','5','6','7','8']
num_list = [3, 1, 4, 5, 8, 9, 7, 2]
plt.bar(range(len(num_list)), num_list, color='b', tick_label=name_list)
plt.show()

import matplotlib.pyplot as plt
import numpy as np

x=np.linspace(0,10,100)
y=np.sin(x)
plt.plot(x,y,color='r',linestyle='dashdot',linewidth=1)
plt.show()

import numpy as np#導入numpy數學函數庫，以np作爲指代
import matplotlib.pyplot as plt#導入matplotlib繪圖庫，以plt作爲指代
rng = np.random.RandomState(0)#以0爲隨機數種子產生隨機數
x = rng.randn(100)#使用randn函數隨機產生100個符合正態分佈的隨機數給x
y = rng.randn(100)#使用randn函數隨機產生100個符合正態分佈的隨機數給y
colors = rng.rand(100)#使用randn函數隨機產生100個符合正態分佈的隨機數給colors
sizes = 1000 * rng.rand(100)#將點的大小擴充1000倍
plt.scatter(x, y, c=colors, s=sizes, alpha=0.3, cmap='viridis')#scatter函數繪製散點圖。分別以x，y爲橫縱座標，顏色隨機產生,表示透明度爲0.3,款色爲翡翠。
plt.colorbar();  #添加漸變色條，展示色階。

import pandas as pd
import  numpy as nnp
rowIndex = [];
for i in range(97,107):
    rowIndex.append(chr(i))
dB = {
            "animal":["cat","cat","snake","dog","dog","cat","snake","cat","dog","dog"],
            "age":["2.5","3.0","0.5","NaN","5.0","2.0","4.5","NaN","7.0","3.0"],
            "priority":["yes","yes","no","yes","no","no","no","yes","no","no"],
            "visits":["1","3","2","3","2","3","1","1","2","1"]
        }
tb = pd.DataFrame(dB, index=rowIndex)
print("表格爲\n")
print(tb,"\n")
print("頭五行\n")
print(tb.head(5),"\n")
print("後三行\n")
print(tb.tail(3),"\n")
tb.sort_values(['age'])
print("按age排序\n")
print(tb)