这将在GUI中显示图形:
import matplotlib.pyplot as plt
plt.plot([1, 2, 3], [1, 4, 9])
plt.show()
但我如何将图形保存到文件(例如foo.png)中?
这将在GUI中显示图形:
import matplotlib.pyplot as plt
plt.plot([1, 2, 3], [1, 4, 9])
plt.show()
但我如何将图形保存到文件(例如foo.png)中?
当前回答
import matplotlib.pyplot as plt
plt.savefig("image.png")
在Jupyter Notebook中,您必须在一个单元格中删除plt.show()并添加plt.savefig()以及其他plt代码。图像仍将显示在笔记本中。
其他回答
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()
使用plot()和其他函数创建所需的内容后,可以使用如下子句在绘制到屏幕或文件之间进行选择:
import matplotlib.pyplot as plt
fig = plt.figure(figsize=(4, 5)) # size in inches
# use plot(), etc. to create your plot.
# Pick one of the following lines to uncomment
# save_file = None
# save_file = os.path.join(your_directory, your_file_name)
if save_file:
plt.savefig(save_file)
plt.close(fig)
else:
plt.show()
嗯,我确实建议使用包装器来渲染或控制绘图。示例可以是mpltex(https://github.com/liuyxpp/mpltex)或prettyplotlib(https://github.com/olgabot/prettyplotlib).
import mpltex
@mpltex.acs_decorator
def myplot():
plt.figure()
plt.plot(x,y,'b-',lable='xxx')
plt.tight_layout(pad=0.5)
plt.savefig('xxxx') # the figure format was controlled by the decorator, it can be either eps, or pdf or png....
plt.close()
我基本上经常使用这个装饰器在美国化学学会、美国物理学会、美国光学学会、Elsivier等各种期刊上发表学术论文。
示例如下图所示(https://github.com/MarkMa1990/gradientDescent):
import matplotlib.pyplot as plt
plt.savefig("image.png")
在Jupyter Notebook中,您必须在一个单元格中删除plt.show()并添加plt.savefig()以及其他plt代码。图像仍将显示在笔记本中。
你可以这样做:
def plotAFig():
plt.figure()
plt.plot(x,y,'b-')
plt.savefig("figurename.png")
plt.close()