python - 使用 matplotlib 填充行与行之间的空间

Question

我正在编写一个 python 程序，该程序将 .csv 文件中的数据绘制为财务值与日期，格式为月-日-年。一条线代表财务值(value)的较高估计值，另一条线代表较低的估计值，第三条线代表平均估计值。我试图让绘图用红色填充上限和下限估计之间的区域，并覆盖代表平均值的黑线。我可以将每个数据集绘制成一条线，但出于某种原因，它不允许我用红色填充上限和下限之间的空间。下图显示了几何形状，我正在尝试填充红线之间的空间。当我使用 fill_between 命令运行代码时，我收到消息“condition = ~(np.isfinite(a))。任何人都可以发现我的问题所在。我从 .csv 文件和完整的代码以更好地理解机制，或缺乏机制。

#!/usr/bin/python
import csv
import sys
import datetime
from pylab import *
from matplotlib.ticker import MaxNLocator

date      = []
Median    = []
Upper     = []
Lower     = []

inp           = open('Checking.csv','rt')
try:
    reader = csv.reader(inp)
    for row in reader:
        Init_Date = row[0]
        if(Init_Date[0:3] == 'Jan'):   Month = 1
        elif(Init_Date[0:3] == 'Feb'): Month = 2
        elif(Init_Date[0:3] == 'Mar'): Month = 3
        elif(Init_Date[0:3] == 'Apr'): Month = 4
        elif(Init_Date[0:3] == 'May'): Month = 5
        elif(Init_Date[0:3] == 'Jun'): Month = 6
        elif(Init_Date[0:3] == 'Jul'): Month = 7
        elif(Init_Date[0:3] == 'Aug'): Month = 8
        elif(Init_Date[0:3] == 'Sep'): Month = 9
        elif(Init_Date[0:3] == 'Oct'): Month = 10
        elif(Init_Date[0:3] == 'Nov'): Month = 11
        else: Month = 12

        day  = Init_Date[4:6]
        year = Init_Date[-3:-1]

        Median.append(row[1])
        Upper.append(row[2])
        Lower.append(row[3])
        dates = str(Month) + '/' + str(day).strip() + '/' + str(year)
        date.append(datetime.datetime.strptime(dates,'%m/%d/%y'))
finally:
    inp.close()

fig, plt = plt.subplots()
matplotlib.rc('xtick',labelsize=18)
matplotlib.rc('ytick',labelsize=18)
x = date
y = Median
y1 = Upper
y2 = Lower
plt.set_xlabel(r'$Date$',fontsize = 18)
plt.set_ylabel(r'$Y-Value$',fontsize = 18)
plt.plot(x, y1, color = 'red')
plt.plot(x, y2, color = 'red')
plt.fill_between(x,y2,y1,interpolate=True,color='red')
plt.plot(x, y, color = 'black')
plt.xaxis.set_major_locator(MaxNLocator(nbins = 12))
fig.savefig("Test.png")

测试数据

Mar 2 2014  18339.1     18734.15    17944.05
Mar 3 2014  18280.33    18675.39    17885.26
Mar 4 2014  18220.61    18614.84    17826.39
Mar 5 2014  18160.77    18552.15    17769.39
Mar 6 2014  18100.92    18493.55    17708.28
Mar 7 2014  18042.18    18431.77    17652.59
Mar 8 2014  17983.51    18371.31    17595.71
Mar 9 2014  17577.67    17959.34    17196
Mar 10 2014 17517.87    17898.33    17137.42
Mar 11 2014 15956.97    16309.96    15603.98
Mar 12 2014 15403.36    15746.7     15060.03
Mar 13 2014 15344.04    15684.44    15003.65
Mar 14 2014 20731.34    21171.47    20291.2
Mar 15 2014 22986.67    23469.15    22504.18
Mar 16 2014 22926.7     23408.98    22444.42
Mar 17 2014 22867.46    23348.73    22386.19
Mar 18 2014 22541.08    23015.78    22066.39
Mar 19 2014 22481.86    22955.47    22008.25
Mar 20 2014 22420.94    22895.56    21946.32
Mar 21 2014 22361.48    22832.68    21890.28
Mar 22 2014 22301.09    22771.64    21830.53
Mar 23 2014 21972.47    22435.43    21509.52
Mar 24 2014 21913.41    22376.04    21450.77
Mar 25 2014 21251.91    21701.94    20801.88
Mar 26 2014 21192.85    21642.57    20743.12
Mar 27 2014 21133.16    21582       20684.31
Mar 28 2014 21074.7     21521.39    20628.01
Mar 29 2014 21014.04    21461.03    20567.05
Mar 30 2014 24122.28    24627.21    23617.35
Mar 31 2014 24063.07    24566.59    23559.55

Answer 1

错误是由于传递给 fill_between 的数据是 string 类型引起的。如果您在绘图之前打印 y、y1 和y2 变量，您可以看到问题:

>>> print(y)
['18339.1', '18280.33', '18220.61', '18160.77', '18100.92', '18042.18', '17983.51', '17577.67', '17517.87', '15956.97', '15403.36', '15344.04', '20731.34', '22986.67', '22926.7', '22867.46', '22541.08', '22481.86', '22420.94', '22361.48', '22301.09', '21972.47', '21913.41', '21251.91', '21192.85', '21133.16', '21074.7', '21014.04', '24122.28', '24063.07']

>>> print(y1)
['18734.15', '18675.39', '18614.84', '18552.15', '18493.55', '18431.77', '18371.31', '17959.34', '17898.33', '16309.96', '15746.7', '15684.44', '21171.47', '23469.15', '23408.98', '23348.73', '23015.78', '22955.47', '22895.56', '22832.68', '22771.64', '22435.43', '22376.04', '21701.94', '21642.57', '21582', '21521.39', '21461.03', '24627.21', '24566.59']

>>> print(y2)
['17944.05', '17885.26', '17826.39', '17769.39', '17708.28', '17652.59', '17595.71', '17196', '17137.42', '15603.98', '15060.03', '15003.65', '20291.2', '22504.18', '22444.42', '22386.19', '22066.39', '22008.25', '21946.32', '21890.28', '21830.53', '21509.52', '21450.77', '20801.88', '20743.12', '20684.31', '20628.01', '20567.05', '23617.35', '23559.55']

解决方案是在绘图之前将它们转换为数字类型(例如 float)。最简单的地方是您构建列表的地方:

Median.append( float(row[1]) )
Upper.append( float(row[2]) )
Lower.append( float(row[3]) )

现在 fill_between 将按预期工作，您的脚本将生成以下图: