"dvipng: not found" when creating matplotlib figure

Question

I try to plot a frequency histogram with matplotlib but it doesn t work and i don t know where is the problem...

import matplotlib.pyplot as plt
import matplotlib.ticker as ticker
import numpy as np

data = np.array([58.35, 71.83, 49.25, 38.89, 12.6, 58.34, 34.5, 11.6, 64.66, \
89.14, 101.84, 26.91, 38.74, 65.03, 35.23, 70.73, 54.52, 73.36, 74.35, \
60.54, 73.52, 24.58, 50.31, 55.63, 14.6, 53.64, 81.6])

fig = plt.figure()
ax = fig.add_subplot(1,1,1)

n, bins, patches=ax.hist(data, 10, facecolor='green', alpha=0.75)

ax.yaxis.set_major_formatter(ticker.FuncFormatter(lambda y, pos: ('%.2f')%(y*1e-3)))
ax.set_ylabel('Frequency (000s)')

plt.show()

A part of the error message :

sh: 1: dvipng: not found
Exception in Tkinter callback
Traceback (most recent call last):
  File "/usr/lib/python2.7/lib-tk/Tkinter.py", line 1535, in __call__
    return self.func(*args)
  File "/usr/lib/pymodules/python2.7/matplotlib/backends/backend_tkagg.py", line 276, in resize
    self.show()
  File "/usr/lib/pymodules/python2.7/matplotlib/backends/backend_tkagg.py", line 348, in draw
    FigureCanvasAgg.draw(self)
  File "/usr/lib/pymodules/python2.7/matplotlib/backends/backend_agg.py", line 451, in draw
    self.figure.draw(self.renderer)
  File "/usr/lib/pymodules/python2.7/matplotlib/artist.py", line 55, in draw_wrapper
    draw(artist, renderer, *args, **kwargs)
  File "/usr/lib/pymodules/python2.7/matplotlib/figure.py", line 1034, in draw
    func(*args)

...

Solution 1

It looks like you are having a problem with the renderer or backend. You might want to try a different backend, by adding this at the beginning of your code:

import matplotlib as mpl
mpl.use('macOsX')

For other renderers, see here: http://matplotlib.org/faq/usage_faq.html#what-is-a-backend

Solution 2

In Ubuntu 14.04 I used this command to solve the problem:

sudo apt-get install dvipng

Solution 3

I found that if you have some Latex distr. installed you may also go with:

 sudo tlmgr install dvipng

This is especially helpful for Mac, alternatively you can use ports:

sudo port install dvipng

Comments

[Warren Weckesser]

"it doesn t work"... What doesn't work? Explain the problem. Do you get an error? An unexpected result?

[user3601754]

Sorry for the lack of explanations...It crashs and I get : sh: 1: dvipng: not found Exception in Tkinter callback

[Ffisegydd]

There must be something wrong either with how you're running the code, or how you've installed it. It runs fine for me on Mac OS X using Python 3.4 and matplotlib 1.4.2.

[cel]

@user3601754, please edit the whole error message into your question. The exact error will help us to understand your problem and others when trying to find a solution for a similar problem.

[gboffi]

@user3601754 I don't see how it comes to call dvipng but if you're on linux you can install dvipng in 30" and see if your problem goes away

[user3601754]

I will try when i m go back home. Here i am, the internet isn t very fast..thanks for help

[tacaswell]

The reason that it is calling divpng is that usetex is True, which means mpl is trying to use LaTeX to render the text on your graph which in turn uses dvipng to turn the dvi output of LaTeX into a png to be include in the raster output.

[mab]

Thanks. Works for Ubuntu 18.04 LTS, too.

[gota]

I don't have sudo permission. what can I do?

[Thiago Falcao]

usually you need sudo permission to install something. try sudo -i to become root, after that try apt-get install dvipng

[pfincent]

With macports, I get an "Error: Port dvipng not found".

[LemurPwned]

@pfincent interesting, according to this: ports.macports.org/port/dvipng , it should be available. Maybe try updating the ports sudo port -v selfupdate?

[pfincent]

I had just installed macports a few minutes earlier before trying to download dvipng, so I didn't assume that was necessary, but it did indeed fix the problem. Thanks!