Save multiple plots in a single PDF file

plotting module

def plotGraph(X,Y):
fignum = random.randint(0,sys.maxint)
plt.figure(fignum)
### Plotting arrangements ###
return fignum

main module

import matplotlib.pyplot as plt
### tempDLStats, tempDLlabels are the argument
plot1 = plotGraph(tempDLstats, tempDLlabels)
plot2 = plotGraph(tempDLstats_1, tempDLlabels_1)
plot3 = plotGraph(tempDLstats_2, tempDLlabels_2)
plt.show()

I want to save all the graphs plot1, plot2, plot3 to a single PDF file. Is there any way to achieve it? I can't include the plotGraph function in the main module.

There's a function named pyplot.savefig but that seems to work only with a single figure. Is there any other way to accomplish it?

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小开
最佳答案

Never mind got the way to do it. 

def plotGraph(X,Y):
fignum = random.randint(0,sys.maxint)
fig = plt.figure(fignum)
### Plotting arrangements ###
return fig

------ plotting module ------

----- mainModule ----

 import matplotlib.pyplot as plt
### tempDLStats, tempDLlabels are the argument
plot1 = plotGraph(tempDLstats, tempDLlabels)
plot2 = plotGraph(tempDLstats_1, tempDLlabels_1)
plot3 = plotGraph(tempDLstats_2, tempDLlabels_2)
plt.show()
plot1.savefig('plot1.png')
plot2.savefig('plot2.png')
plot3.savefig('plot3.png')

----- mainModule -----

小开

For multiple plots in a single pdf file you can use PdfPages

In the plotGraph function you should return the figure and than call savefig of the figure object.

------ plotting module ------

def plotGraph(X,Y):
fig = plt.figure()
### Plotting arrangements ###
return fig

------ plotting module ------

----- mainModule ----

from matplotlib.backends.backend_pdf import PdfPages


plot1 = plotGraph(tempDLstats, tempDLlabels)
plot2 = plotGraph(tempDLstats_1, tempDLlabels_1)
plot3 = plotGraph(tempDLstats_2, tempDLlabels_2)


pp = PdfPages('foo.pdf')
pp.savefig(plot1)
pp.savefig(plot2)
pp.savefig(plot3)
pp.close()
小开 
import datetime
import numpy as np
from matplotlib.backends.backend_pdf import PdfPages
import matplotlib.pyplot as plt


# Create the PdfPages object to which we will save the pages:
# The with statement makes sure that the PdfPages object is closed properly at
# the end of the block, even if an Exception occurs.
with PdfPages('multipage_pdf.pdf') as pdf:
plt.figure(figsize=(3, 3))
plt.plot(range(7), [3, 1, 4, 1, 5, 9, 2], 'r-o')
plt.title('Page One')
pdf.savefig()  # saves the current figure into a pdf page
plt.close()


plt.rc('text', usetex=True)
plt.figure(figsize=(8, 6))
x = np.arange(0, 5, 0.1)
plt.plot(x, np.sin(x), 'b-')
plt.title('Page Two')
pdf.savefig()
plt.close()


plt.rc('text', usetex=False)
fig = plt.figure(figsize=(4, 5))
plt.plot(x, x*x, 'ko')
plt.title('Page Three')
pdf.savefig(fig)  # or you can pass a Figure object to pdf.savefig
plt.close()


# We can also set the file's metadata via the PdfPages object:
d = pdf.infodict()
d['Title'] = 'Multipage PDF Example'
d['Author'] = u'Jouni K. Sepp\xe4nen'
d['Subject'] = 'How to create a multipage pdf file and set its metadata'
d['Keywords'] = 'PdfPages multipage keywords author title subject'
d['CreationDate'] = datetime.datetime(2009, 11, 13)
d['ModDate'] = datetime.datetime.today()
小开

If someone ends up here from google, looking to convert a single figure to a .pdf (that was what I was looking for):

import matplotlib.pyplot as plt


f = plt.figure()
plt.plot(range(10), range(10), "o")
plt.show()


f.savefig("foo.pdf", bbox_inches='tight')

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