Question

我是matplotlib的新手，不会在Latex中使用图形。视觉输出为图形，但是：

为什么没有pdf输出？

import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
import os #to remove a file
import datetime 
from matplotlib.backends.backend_pdf import PdfPages
#######################

Val1 = [1,2,3,4,5,6,7,8,9,9,5,5] # in kWh
Val2 = [159,77,1.716246,2,4,73,128,289,372,347,354,302] #in m³


index = ['Apr', 'Mai', 'Jun', 'Jul','Aug','Sep','Okt','Nov','Dez','Jan', 'Feb', 'Mrz']
df = pd.DataFrame({'Val1': Val1,'Val2': Val2}, index=index)



with PdfPages('aas2s.pdf') as pdf:

plt.rc('text', usetex=True)
params = {'text.latex.preamble' : [r'\usepackage{siunitx}', r'\usepackage{amsmath}']}
plt.rcParams['font.family'] = 'serif'
plt.rcParams['font.serif'] = 'Liberation'
plt.rcParams.update(params)
plt.figure(figsize=(8, 6))
plt.rcParams.update({'font.size': 12}) 
ax = df[['Val1','Val2']].plot.bar(color=['navy','maroon'])

plt.xlabel('X Achse m')
plt.ylabel('Y Achse Taxi quer ')
plt.legend(loc='upper left', frameon=False)
plt.title('Franz jagt im komplett verwahrlosten Taxi quer durch Bayern')
plt.show()

pdf.savefig()
plt.close()

该错误被称为：ValueError：没有这样的数字：无

如何获得第二个“ Y”轴作为第二个值？

Answer 1

通常，savefig应先称为 show。参见例如

Matplotlib (pyplot) savefig outputs blank image
How come pyplot from Matplotlib doesn't allow you to save an image after you show it?（还有更多说明）

第二，您想在创建的图形中生成图，而不是创建新图，因此使用

fig, ax = plt.subplots(figsize=...)
df.plot(..., ax=ax)

，然后调用轴的方法（面向对象的样式）。

总共

import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.backends.backend_pdf import PdfPages
#######################

Val1 = [1,2,3,4,5,6,7,8,9,9,5,5] # in kWh
Val2 = [159,77,1.716246,2,4,73,128,289,372,347,354,302] #in m³


index = ['Apr', 'Mai', 'Jun', 'Jul','Aug','Sep','Okt','Nov','Dez','Jan', 'Feb', 'Mrz']
df = pd.DataFrame({'Val1': Val1,'Val2': Val2}, index=index)



with PdfPages('aas2s.pdf') as pdf:

    plt.rc('text', usetex=True)
    params = {'text.latex.preamble' : [r'\usepackage{siunitx}', r'\usepackage{amsmath}']}
    plt.rcParams['font.family'] = 'serif'
    plt.rcParams['font.serif'] = 'Times New Roman'
    plt.rcParams.update(params)

    fig, ax = plt.subplots(figsize=(8, 6))
    plt.rcParams.update({'font.size': 12}) 
    df[['Val1','Val2']].plot.bar(color=['navy','maroon'], ax=ax)

    ax.set_xlabel('X Achse m')
    ax.set_ylabel('Y Achse Taxi quer ')
    ax.legend(loc='upper left', frameon=False)
    ax.set_title('Franz jagt im komplett verwahrlosten Taxi quer durch Bayern')
    pdf.savefig()
    plt.show()
    plt.close()

现在，如果您仍然需要在显示该图形之后保存该图形，可以通过将其专门用作savefig

的参数来进行保存

plt.show()
pdf.savefig(fig)

Matplotlib pdf输出

1 个答案: