I have a piece of code which gets called by a different function, carries out some calculations for me and then plots the output to a file. Seeing as the whole script can take a while to run for larger datasets and since I may want to analyse multiple datasets at a given time I start it in screen then disconnect and close my putty session and check back on it the next day. I am using Ubuntu 14.04. My code looks as follows (I have skipped the calculations):
import shelve
import os, sys, time
import numpy
import timeit
import logging
import csv
import itertools
import graph_tool.all as gt
import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt
plt.ioff()
#Do some calculations
print 'plotting indeg'
# Let's plot its in-degree distribution
in_hist = gt.vertex_hist(g, "in")
y = in_hist[0]
err = numpy.sqrt(in_hist[0])
err[err >= y] = y[err >= y] - 1e-2
plt.figure(figsize=(6,4))
plt.errorbar(in_hist[1][:-1], in_hist[0], fmt="o",
label="in")
plt.gca().set_yscale("log")
plt.gca().set_xscale("log")
plt.gca().set_ylim(0.8, 1e5)
plt.gca().set_xlim(0.8, 1e3)
plt.subplots_adjust(left=0.2, bottom=0.2)
plt.xlabel("$k_{in}$")
plt.ylabel("$NP(k_{in})$")
plt.tight_layout()
plt.savefig("in-deg-dist.png")
plt.close()
print 'plotting outdeg'
#Do some more stuff
The script runs perfectly happily until I get to the plotting commands. To try and get to the root of the problem I am currently running it in putty without screen and with no X11 applications. The ouput I get is the following:
plotting indeg
PuTTY X11 proxy: unable to connect to forwarded X server: Network error: Connection refused
: cannot connect to X server localhost:10.0
I presume this is caused by the code trying to open a window but I thought that by explicitely setting plt.off() that would be disabled. Since it wasn't I followed this thread (Generating matplotlib graphs without a running X server ) and specified the backend, but that didn't solve the problem either. Where might I be going wrong?