python笔记----matplotlib（2）：条形图、散点图

#coding=utf-8
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
#条形图

reviews = pd.read_csv("fandango_scores.csv")
cols = ["FILM","RT_user_norm","Metacritic_user_nom","IMDB_norm","Fandango_Ratingvalue","Fandango_Stars"]
norm_reviews = reviews[cols]#从矩阵取以上列

num_cols = ["RT_user_norm","Metacritic_user_nom","IMDB_norm","Fandango_Ratingvalue","Fandango_Stars"]
bar_heights = norm_reviews.ix[0,num_cols].values    #取这些列的数据 作为y轴的值

from numpy import arange
bar_positions = arange(5) + 0.75    #5条柱子与y轴的距离  作为x轴的值
fig,ax = plt.subplots()
ax.bar(bar_positions,bar_heights,0.8)#竖图 ax.bar绘制的是条形图
#ax.barh(bar_positions,bar_heights,0.8)#横图 柱子宽度0.8
plt.show()

print("--------------------------")

#散点图  scatter
flg,ax = plt.subplots()
ax.scatter(norm_reviews["Fandango_Ratingvalue"],norm_reviews["RT_user_norm"])
ax.set_xlabel("Fandango")
ax.set_ylabel("Rotten Tomatoes")
plt.show()

fig,ax = plt.subplots()
#ax.hist(norm_reviews["Fandango_Ratingvalue"])
ax.hist(norm_reviews["Fandango_Ratingvalue"],bins = 20)#分成20个柱子
#ax.hist(norm_reviews["Fandango_Ratingvalue"],range = (1,6),bins = 20)#只绘制1-6的数据
#ax.set_ylin(0,50)#设置y轴范围
plt.show()