color_cycle warning with matplotlib 1.5

[chadkennedyonline]

When executing

#format the book
%matplotlib inline
%load_ext autoreload
%autoreload 2  
from __future__ import division, print_function
import sys
sys.path.insert(0,'./code')
from book_format import load_style
load_style()

from any page, I get the following warning:

D:\Chad\Documents\WinPython-64bit-3.4.3.6\python-3.4.3.amd64\lib\site-packages\matplotlib\__init__.py:876: UserWarning: axes.color_cycle is deprecated and replaced with axes.prop_cycle; please use the latter.
  warnings.warn(self.msg_depr % (key, alt_key))

This Python distro is using Matplotlib 1.5.0rc3. I have confirmed that changing the axes.color_cycle line in 538.json to

  "axes.prop_cycle": "cycler('color', ['#6d904f','#013afe', '#202020','#fc4f30','#e5ae38','#A60628','#30a2da','#008080','#7A68A6','#CF4457','#188487','#E24A33'])",

fixes the warning. But I am unsure how to make the json file conditional based on Matplotlib version, so as to be backwards compatible with older distributions.

[rlabbe]

I just pushed a version that detects the matplotlib version and uses the appropriate settings. Let me know if it doesn't work for you.

[dnstanciu]

Hi, I downloaded a fresh copy and I get this error when running the snippet posted by @chadkennedyonline :

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-25-a550bbe40f47> in <module>()
      7 sys.path.insert(0,'./code')
      8 from book_format import load_style
----> 9 load_style()

/home/dragos/Projects/Kalman-and-Bayesian-Filters-in-Python/code/book_format.pyc in load_style(directory, name)
    130         s.pop("axes.color_cycle", None)
    131 
--> 132     plt.rcParams.update(s)
    133     reset_axis ()
    134     np.set_printoptions(suppress=True)

ValueError: dictionary update sequence element #0 has length 1; 2 is required

When I print (s), I get 1. I'm guessing that rcParams expects a (key,value) pair. Could you please fix this? Not being able to run the first cell messes up the formatting... Thank you!

[rlabbe]

@dnstanciu can you tell me your environment - Python version, IPython version, OS, python package if you are using one(anaconda or whatever)? Also the matplotlib version, as my code change behaves differently based on the matplotlib version. I cannot duplicate this here, so I'm hoping this will help me diagnose the problem.

Follow up: you said when you print s you get '1'? As in the number 1? When I print s I get

{'figure.facecolor': '#ffffff', 'font.size': 14.0, 'figure.subplot.hspace': 0.5, 'examples.directory': '', 'axes.grid': True, 'ytick.major.size': 0, 'figure.subplot.bottom': 0.07, 'axes.facecolor': '#ffffff', 'axes.color_cycle': ['#6d904f', '#013afe', '#202020', '#fc4f30', '#e5ae38', '#A60628', '#30a2da', '#008080', '#7A68A6', '#CF4457', '#188487', '#E24A33'], 'savefig.edgecolor': '#f0f0f0', 'axes.linewidth': 3.0, 'grid.linestyle': '-', 'patch.linewidth': 0.5, 'savefig.facecolor': '#f0f0f0', 'axes.axisbelow': True, 'axes.labelsize': 'large', 'axes.edgecolor': '#f0f0f0', 'xtick.minor.size': 0, 'grid.color': '#cbcbcb', 'patch.edgecolor': '#f0f0f0', 'legend.scatterpoints': 1, 'legend.fancybox': True, 'lines.linewidth': 3, 'axes.titlesize': 'x-large', 'figure.subplot.right': 0.95, 'lines.solid_capstyle': 'butt', 'ytick.minor.size': 0, 'grid.linewidth': 2.0, 'xtick.major.size': 0, 'figure.subplot.left': 0.08}

The first lines of the load_style() function read:

if sys.version_info[0] >= 3:
    s = json.load(open(os.path.join(directory, "code/538.json")))
else:
    s = json.load(open(directory + "/code/538.json"), object_hook=_decode_dict)

I suspect you are not reading the 538.json file for some reason. Are you in the base directory for the book? This code uses relative directories, where directory parameter has the default value '.'.

[dnstanciu]

When I got the error, my setup consisted of:
Python 2.7.6; IPython 4.0.0; Ubuntu 14.04; not using anaconda; matplotlib 1.3.1; running ipython notebook from the base directory.

After updating all my PIP packages, I got a new error:

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-34-a550bbe40f47> in <module>()
      7 sys.path.insert(0,'./code')
      8 from book_format import load_style
----> 9 load_style()

/home/dragos/Projects/testkalmanbook/Kalman-and-Bayesian-Filters-in-Python/code/book_format.py in load_style(directory, name)
    127 
    128     if version[0] > 1 or (version[0] == 1 and version[1] >= 5):
--> 129         s["axes.prop_cycle"] = "cycler('color', ['#6d904f','#013afe', '#202020','#fc4f30','#e5ae38','#A60628','#30a2da','#008080','#7A68A6','#CF4457','#188487','#E24A33'])"
    130         s.pop("axes.color_cycle", None)
    131 

TypeError: 'unicode' object does not support item assignment

I realized that the s dictionary was being overwritten in line 127:

version = [int(s) for s in matplotlib.__version__.split('.')]

That explains why I was getting 1 instead of the JSON settings...
So I changed s to version_no in line 126 and it all works ok now! I've submitted a pull request, if you'd like to accept my small contribution: #70 . Cheers!

[rlabbe]

I've accepted the pull request (thanks!) and haven't heard of any more problems, so I'm closing it. Please reopen if you are still having problems.