matplotlib的初次使用

初次嘗試python的matplotlib，由於論文有一堆數據要處理，只能自學。就是所謂的用到什麼學什麼吧。

下面記錄一下：首先統計全部閾值的頻率，用dictionary來存儲；參考官方網址對plt.bar()的各個參數解釋，創建相應的柱狀圖。

代碼以下：

# encoding:utf-8
import numpy as np
import math
from matplotlib import pyplot as plt

# 0的字典
dic0 = {}
# 1的字典
dic1 = {}

def autolabel(rects):
    for rect in rects:
        height = rect.get_height()
        plt.text(rect.get_x() + rect.get_width() / 2. - 0.2, 1.03 * height, '%d' % height)

total_width,n = 0.4,2
width = total_width/n

with open(r'/Users/binryang/Desktop/運行結果/balloons_qp25_16.txt', 'r') as f:
    for line in f:
        a = line.split()
        key = int(math.ceil(float(a[1])))
        if key == 0 or key > 10:
            continue
        if a[0] == '0':
            if key in dic0.keys():
                dic0[key] = dic0[key] + 1
            else:
                dic0[key] = 1
        else:
            if key+width in dic1.keys():
                dic1[key+width] = dic1[key+width] + 1
            else:
                dic1[key+width] = 1


# items0 = dic0.items()
# items0.sort()
#
# items1 = dic1.items()
# items1.sort()
#
# print dic0
# print dic1

# plt.figure()
# plt.plot(dic0.keys(),dic0.values())
# plt.plot(dic1.keys(),dic1.values())

m = plt.bar(dic0.keys(), dic0.values(),width,label='no-division')
n = plt.bar(dic1.keys(),dic1.values(),width,label='division')
autolabel(m)
autolabel(n)
plt.xlabel('difference value')
plt.ylabel('numbers')
plt.title('numbers of difference value')
plt.legend()

# plt.xticks(dic0.keys())

# plt.subplot(212)
# plt.bar(dic1.keys(),dic1.values())
# plt.xlabel('difference value')
# plt.ylabel('numbers')
# plt.xticks(dic1.keys())
plt.savefig('bar.pdf')
plt.show()

生成的圖片以下：

吐槽一下：插入圖片不能用pdf，致使放大失真嚴重