Deprecations for Matplotlib-3.0.0rc2

[stonebig]

with matplotlib-3.0.0rc2, some annoying deprecation warning do arrive

apparently, holoviews still generates the now unwanted parameters.

https://github.com/ioam/holoviews/blob/63cfac9e104b134f9dcb7eb0f1b16196df16e2db/holoviews/plotting/mpl/plot.py#L133..L134

see:

• https://matplotlib.org/devdocs/api/next_api_changes/2018-05-15-AL.html
  or
• https://matplotlib.org/devdocs/api/api_changes.html

[jlstevens]

Thanks for reporting this!

It is good to have users report what is coming up in upcoming matplotlib versions as we use the stable releases for ourselves and for testing.

[stonebig]

so you will test against matplotlib-3.0.0 (on Python 3.5+ branches), if it's released tomorrow ?

[philippjfr]

I'll do my best.

[stonebig]

matplotlib-3.0 final is out.

[philippjfr]

Thanks, I'll try it now.

[philippjfr]

Okay I also see those deprecation warnings:

/Users/philippjfr/miniconda/envs/anacondaviz/lib/python3.6/site-packages/matplotlib/__init__.py:846: MatplotlibDeprecationWarning: 
The text.latex.unicode rcparam was deprecated in Matplotlib 2.2 and will be removed in 3.1.
  "2.2", name=key, obj_type="rcparam", addendum=addendum)
/Users/philippjfr/miniconda/envs/anacondaviz/lib/python3.6/site-packages/matplotlib/__init__.py:855: MatplotlibDeprecationWarning: 
examples.directory is deprecated; in the future, examples will be found relative to the 'datapath' directory.
  "found relative to the 'datapath' directory.".format(key))
/Users/philippjfr/miniconda/envs/anacondaviz/lib/python3.6/site-packages/matplotlib/__init__.py:846: MatplotlibDeprecationWarning: 
The text.latex.unicode rcparam was deprecated in Matplotlib 2.2 and will be removed in 3.1.
  "2.2", name=key, obj_type="rcparam", addendum=addendum)
/Users/philippjfr/miniconda/envs/anacondaviz/lib/python3.6/site-packages/matplotlib/__init__.py:855: MatplotlibDeprecationWarning: 
examples.directory is deprecated; in the future, examples will be found relative to the 'datapath' directory.
  "found relative to the 'datapath' directory.".format(key))

But I can't figure out where they're coming from, we do load and ship a custom rc file but it specifies none of the options it's warning about.

[philippjfr]

Nevermind I found it, the default rcparams in matplotlib still set these values. We use a context manager to temporarily override the options and when they are restored the warnings are generated.

[philippjfr]

Now fixed in #3013

[stonebig]

I don't understand, I still have some with latest holoviews-1.11.0a6

[stonebig]

unless it's an effect from previous packages tried in my notebook... checking

[stonebig]

also the last one... something is wired, maybe it's matplotlib itself

[stonebig]

reducing to my minimum I still have the issue... not sure where it's created

[stonebig]

don't know exactly how to set a

warnings.filterwarnings("ignore", category=mpl.cbook.MatplotlibDeprecationWarning)

[stonebig]

ok, workarounded in waiting of a better solution

import warnings
import matplotlib as mpl
# Holoviews
# for more example, see http://holoviews.org/Tutorials/index.html
import numpy as np
import holoviews as hv
hv.extension('matplotlib')
dots = np.linspace(-0.45, 0.45, 11)
fractal = hv.Image(image)

layouts = {y: (fractal * hv.Points(fractal.sample([(i,y) for i in dots])) +
               fractal.sample(y=y) )
            for y in np.linspace(0, 0.45,11)}
warnings.filterwarnings("ignore", category=mpl.cbook.MatplotlibDeprecationWarning)
hv.HoloMap(layouts, kdims=['Y']).collate().cols(2)

[philippjfr]

I'll have another look, but I have mpl 3.0.0 and can't reproduce any warnings.

[philippjfr]

Nevermind I can reproduce and I've got a fix.

[philippjfr]

Merged that PR prematurely, still seeing those warnings.

[philippjfr]

This one seems to have done it: #3058