Matplotlib - How to plot a high resolution graph?

I've used matplotlib for plotting some experimental results (discussed it in here: Looping over files and plotting. However, saving the picture by clicking right to the image gives very bad quality / low resolution images.

from glob import glob
import numpy as np
import matplotlib.pyplot as plt
import matplotlib as mpl

# loop over all files in the current directory ending with .txt
for fname in glob("./*.txt"):
    # read file, skip header (1 line) and unpack into 3 variables
    WL, ABS, T = np.genfromtxt(fname, skip_header=1, unpack=True)

    # first plot
    plt.plot(WL, T, label='BN', color='blue')

    plt.xlabel('Wavelength (nm)')
    plt.xlim(200,1000)
    plt.ylim(0,100)
    plt.ylabel('Transmittance, %')
    mpl.rcParams.update({'font.size': 14})
    #plt.legend(loc='lower center')
    plt.title('')
    plt.show()
    plt.clf()


    # second plot
    plt.plot(WL, ABS, label='BN', color='red')
    plt.xlabel('Wavelength (nm)')
    plt.xlim(200,1000)
    plt.ylabel('Absorbance, A')
    mpl.rcParams.update({'font.size': 14})
    #plt.legend()
    plt.title('')
    plt.show()
    plt.clf()

Example graph of what I'm looking for: example graph

You can use savefig() to export to an image file:

plt.savefig('filename.png')

In addition, you can specify the dpi argument to some scalar value, for example:

plt.savefig('filename.png', dpi=300)

Use plt.figure(dpi=1200) before all your plt.plot... and at the end use plt.savefig(...).

For future readers who found this question while trying to save high resolution images from matplotlib as I am, I have tried some of the answers above and elsewhere, and summed them up here.

Best result: plt.savefig('filename.pdf')

and then converting this pdf to a png on the command line so you can use it in powerpoint:

pdftoppm -png -r 300 filename.pdf filename

OR simply opening the pdf and cropping to the image you need in adobe, saving as a png and importing the picture to powerpoint

Less successful test #1: plt.savefig('filename.png', dpi=300)

This does save the image at a bit higher than the normal resolution, but it isn't high enough for publication or some presentations. Using a dpi value of up to 2000 still produced blurry images when viewed close up.

Less successful test #2: plt.savefig('filename.pdf')

This cannot be opened in Microsoft Office Professional Plus 2016 (so no powerpoint), same with Google Slides.

Less successful test #3: plt.savefig('filename.svg')

This also cannot be opened in powerpoint or Google Slides, with the same issue as above.

Less successful test #4: plt.savefig('filename.pdf')

and then converting to png on the command line:

convert -density 300 filename.pdf filename.png

but this is still too blurry when viewed close up.

Less successful test #5: plt.savefig('filename.pdf')

and opening in GIMP, and exporting as a high quality png (increased the file size from ~100 KB to ~75 MB)

Less successful test #6: plt.savefig('filename.pdf')

and then converting to jpeg on the command line:

pdfimages -j filename.pdf filename

This did not produce any errors but did not produce an output on Ubuntu even after changing around several parameters.

You can save your graph as svg for a lossless quality:

import matplotlib.pylab as plt

x = range(10)

plt.figure()
plt.plot(x,x)
plt.savefig("graph.svg")

For saving the graph:

matplotlib.rcParams['savefig.dpi'] = 300

For displaying the graph when you use plt.show():

matplotlib.rcParams["figure.dpi"] = 100

Just add them at the top