<p dir="auto">I am using  Python 3.4.4 |Anaconda 2.3.0 (64-bit)  on win64 bits, with latest  matplotlib  and  pyqt  updated by  conda install xx<br>
for the following code, if I use unicode title in the for-loop, the images are shown with their corretced direction, i.e., the head is toward up like which is in original image. However, if I use English title, the images are upside-down: the people's head is toward earth</p>
<p dir="auto">This can be observed for both  TkAgg  and  Qt5Agg</p>
<div class="highlight highlight-source-python notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="#coding=utf-8
import matplotlib
#~ matplotlib.rcParams['backend'] = 'TkAgg'
matplotlib.rcParams['backend'] = 'Qt5Agg'

from pylab import *
import PIL.Image as Image

im=Image.open('Mario cosplay.jpg').convert('L')

orgsize=im.size
newsize=[int(i/4) for i in orgsize]

subplot(2,3,1)
imshow(im, cmap='gray', vmin=0, vmax=255)
title('original pic', fontsize=20);

filters=[Image.NEAREST, Image.BILINEAR, Image.BICUBIC, Image.ANTIALIAS]
filtersName=['NEAREST', 'BILINEAR', 'BICUBIC', 'ANTIALIAS']
for k in range(len(filters)):
    subplot(2,3,k+2)
    im1=im.resize(newsize, filters[k])
    imshow(im1, cmap='gray', vmin=0, vmax=255)
    title('原图的1/%i，插值法：%s' %  (4, filtersName[k]), fontsize=20)       # head up
    title('size: 1/%i，interpolation: %s' %  (4, filtersName[k]), fontsize=20)    # head down

gcf().tight_layout()

show()"><pre class="notranslate"><span class="pl-c">#coding=utf-8</span>
<span class="pl-k">import</span> <span class="pl-s1">matplotlib</span>
<span class="pl-c">#~ matplotlib.rcParams['backend'] = 'TkAgg'</span>
<span class="pl-s1">matplotlib</span>.<span class="pl-s1">rcParams</span>[<span class="pl-s">'backend'</span>] <span class="pl-c1">=</span> <span class="pl-s">'Qt5Agg'</span>

<span class="pl-k">from</span> <span class="pl-s1">pylab</span> <span class="pl-k">import</span> <span class="pl-c1">*</span>
<span class="pl-k">import</span> <span class="pl-v">PIL</span>.<span class="pl-v">Image</span> <span class="pl-k">as</span> <span class="pl-v">Image</span>

<span class="pl-s1">im</span><span class="pl-c1">=</span><span class="pl-v">Image</span>.<span class="pl-en">open</span>(<span class="pl-s">'Mario cosplay.jpg'</span>).<span class="pl-en">convert</span>(<span class="pl-s">'L'</span>)

<span class="pl-s1">orgsize</span><span class="pl-c1">=</span><span class="pl-s1">im</span>.<span class="pl-s1">size</span>
<span class="pl-s1">newsize</span><span class="pl-c1">=</span>[<span class="pl-en">int</span>(<span class="pl-s1">i</span><span class="pl-c1">/</span><span class="pl-c1">4</span>) <span class="pl-k">for</span> <span class="pl-s1">i</span> <span class="pl-c1">in</span> <span class="pl-s1">orgsize</span>]

<span class="pl-en">subplot</span>(<span class="pl-c1">2</span>,<span class="pl-c1">3</span>,<span class="pl-c1">1</span>)
<span class="pl-en">imshow</span>(<span class="pl-s1">im</span>, <span class="pl-s1">cmap</span><span class="pl-c1">=</span><span class="pl-s">'gray'</span>, <span class="pl-s1">vmin</span><span class="pl-c1">=</span><span class="pl-c1">0</span>, <span class="pl-s1">vmax</span><span class="pl-c1">=</span><span class="pl-c1">255</span>)
<span class="pl-en">title</span>(<span class="pl-s">'original pic'</span>, <span class="pl-s1">fontsize</span><span class="pl-c1">=</span><span class="pl-c1">20</span>);

<span class="pl-s1">filters</span><span class="pl-c1">=</span>[<span class="pl-v">Image</span>.<span class="pl-v">NEAREST</span>, <span class="pl-v">Image</span>.<span class="pl-v">BILINEAR</span>, <span class="pl-v">Image</span>.<span class="pl-v">BICUBIC</span>, <span class="pl-v">Image</span>.<span class="pl-v">ANTIALIAS</span>]
<span class="pl-s1">filtersName</span><span class="pl-c1">=</span>[<span class="pl-s">'NEAREST'</span>, <span class="pl-s">'BILINEAR'</span>, <span class="pl-s">'BICUBIC'</span>, <span class="pl-s">'ANTIALIAS'</span>]
<span class="pl-k">for</span> <span class="pl-s1">k</span> <span class="pl-c1">in</span> <span class="pl-en">range</span>(<span class="pl-en">len</span>(<span class="pl-s1">filters</span>)):
    <span class="pl-en">subplot</span>(<span class="pl-c1">2</span>,<span class="pl-c1">3</span>,<span class="pl-s1">k</span><span class="pl-c1">+</span><span class="pl-c1">2</span>)
    <span class="pl-s1">im1</span><span class="pl-c1">=</span><span class="pl-s1">im</span>.<span class="pl-en">resize</span>(<span class="pl-s1">newsize</span>, <span class="pl-s1">filters</span>[<span class="pl-s1">k</span>])
    <span class="pl-en">imshow</span>(<span class="pl-s1">im1</span>, <span class="pl-s1">cmap</span><span class="pl-c1">=</span><span class="pl-s">'gray'</span>, <span class="pl-s1">vmin</span><span class="pl-c1">=</span><span class="pl-c1">0</span>, <span class="pl-s1">vmax</span><span class="pl-c1">=</span><span class="pl-c1">255</span>)
    <span class="pl-en">title</span>(<span class="pl-s">'原图的1/%i，插值法：%s'</span> <span class="pl-c1">%</span>  (<span class="pl-c1">4</span>, <span class="pl-s1">filtersName</span>[<span class="pl-s1">k</span>]), <span class="pl-s1">fontsize</span><span class="pl-c1">=</span><span class="pl-c1">20</span>)       <span class="pl-c"># head up</span>
    <span class="pl-en">title</span>(<span class="pl-s">'size: 1/%i，interpolation: %s'</span> <span class="pl-c1">%</span>  (<span class="pl-c1">4</span>, <span class="pl-s1">filtersName</span>[<span class="pl-s1">k</span>]), <span class="pl-s1">fontsize</span><span class="pl-c1">=</span><span class="pl-c1">20</span>)    <span class="pl-c"># head down</span>

<span class="pl-en">gcf</span>().<span class="pl-en">tight_layout</span>()

<span class="pl-en">show</span>()</pre></div>
<p dir="auto"><a target="_blank" rel="noopener noreferrer nofollow" href="https://cloud.githubusercontent.com/assets/7960913/23596979/43168210-026a-11e7-8228-dd43c858b0d5.png"><img src="https://cloud.githubusercontent.com/assets/7960913/23596979/43168210-026a-11e7-8228-dd43c858b0d5.png" alt="chinese_headup" style="max-width: 100%;"></a><br>
<a target="_blank" rel="noopener noreferrer nofollow" href="https://cloud.githubusercontent.com/assets/7960913/23596980/4440d8de-026a-11e7-9235-e4419e206e22.png"><img src="https://cloud.githubusercontent.com/assets/7960913/23596980/4440d8de-026a-11e7-9235-e4419e206e22.png" alt="english_headdown" style="max-width: 100%;"></a></p>
<p dir="auto">When plotting  a lot of subplots (here 6), with long y-labels <em>and</em> tight_layout, the y-axis is reverted.<br>
In this example, it is particularly striking as I am plotting histograms.</p>
<div class="highlight highlight-source-python notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="import matplotlib.pyplot as plt
import numpy as np

alphas = [0.001, 0.1, 1, 10, 1000, 10000]
X = np.random.randn(len(alphas), 1000)

fig, axes = plt.subplots(nrows=len(alphas),  ncols=2)
fig.set_tight_layout(True)
for i, alpha in enumerate(alphas):
    ax = axes[i, 0]
    ax.hist(X[i])
    ax.set_xlabel(&quot;Number of features&quot;, fontweight=&quot;bold&quot;)
    ax.set_ylabel(&quot;Number of genes&quot;, fontweight=&quot;bold&quot;)

    ax = axes[i, 1]
    ax.plot(sorted(X[i]))
    ax.set_ylabel(&quot;Number of genes&quot;, fontweight=&quot;bold&quot;)"><pre class="notranslate"><span class="pl-k">import</span> <span class="pl-s1">matplotlib</span>.<span class="pl-s1">pyplot</span> <span class="pl-k">as</span> <span class="pl-s1">plt</span>
<span class="pl-k">import</span> <span class="pl-s1">numpy</span> <span class="pl-k">as</span> <span class="pl-s1">np</span>

<span class="pl-s1">alphas</span> <span class="pl-c1">=</span> [<span class="pl-c1">0.001</span>, <span class="pl-c1">0.1</span>, <span class="pl-c1">1</span>, <span class="pl-c1">10</span>, <span class="pl-c1">1000</span>, <span class="pl-c1">10000</span>]
<span class="pl-v">X</span> <span class="pl-c1">=</span> <span class="pl-s1">np</span>.<span class="pl-s1">random</span>.<span class="pl-en">randn</span>(<span class="pl-en">len</span>(<span class="pl-s1">alphas</span>), <span class="pl-c1">1000</span>)

<span class="pl-s1">fig</span>, <span class="pl-s1">axes</span> <span class="pl-c1">=</span> <span class="pl-s1">plt</span>.<span class="pl-en">subplots</span>(<span class="pl-s1">nrows</span><span class="pl-c1">=</span><span class="pl-en">len</span>(<span class="pl-s1">alphas</span>),  <span class="pl-s1">ncols</span><span class="pl-c1">=</span><span class="pl-c1">2</span>)
<span class="pl-s1">fig</span>.<span class="pl-en">set_tight_layout</span>(<span class="pl-c1">True</span>)
<span class="pl-k">for</span> <span class="pl-s1">i</span>, <span class="pl-s1">alpha</span> <span class="pl-c1">in</span> <span class="pl-en">enumerate</span>(<span class="pl-s1">alphas</span>):
    <span class="pl-s1">ax</span> <span class="pl-c1">=</span> <span class="pl-s1">axes</span>[<span class="pl-s1">i</span>, <span class="pl-c1">0</span>]
    <span class="pl-s1">ax</span>.<span class="pl-en">hist</span>(<span class="pl-v">X</span>[<span class="pl-s1">i</span>])
    <span class="pl-s1">ax</span>.<span class="pl-en">set_xlabel</span>(<span class="pl-s">"Number of features"</span>, <span class="pl-s1">fontweight</span><span class="pl-c1">=</span><span class="pl-s">"bold"</span>)
    <span class="pl-s1">ax</span>.<span class="pl-en">set_ylabel</span>(<span class="pl-s">"Number of genes"</span>, <span class="pl-s1">fontweight</span><span class="pl-c1">=</span><span class="pl-s">"bold"</span>)

    <span class="pl-s1">ax</span> <span class="pl-c1">=</span> <span class="pl-s1">axes</span>[<span class="pl-s1">i</span>, <span class="pl-c1">1</span>]
    <span class="pl-s1">ax</span>.<span class="pl-en">plot</span>(<span class="pl-en">sorted</span>(<span class="pl-v">X</span>[<span class="pl-s1">i</span>]))
    <span class="pl-s1">ax</span>.<span class="pl-en">set_ylabel</span>(<span class="pl-s">"Number of genes"</span>, <span class="pl-s1">fontweight</span><span class="pl-c1">=</span><span class="pl-s">"bold"</span>)</pre></div>
<p dir="auto"><a target="_blank" rel="noopener noreferrer nofollow" href="https://cloud.githubusercontent.com/assets/184798/22847757/191f0c3a-efa4-11e6-9b64-2b9a098b754c.png"><img src="https://cloud.githubusercontent.com/assets/184798/22847757/191f0c3a-efa4-11e6-9b64-2b9a098b754c.png" alt="mpl_bug" style="max-width: 100%;"></a></p>
<p dir="auto"><strong>Expected outcome</strong></p>
<p dir="auto">Removing the tight layout, the labels collapse, but at least the plots are oriented the correct way.</p>
<p dir="auto"><a target="_blank" rel="noopener noreferrer nofollow" href="https://cloud.githubusercontent.com/assets/184798/22847782/421d5704-efa4-11e6-8956-91f8008c95e5.png"><img src="https://cloud.githubusercontent.com/assets/184798/22847782/421d5704-efa4-11e6-8956-91f8008c95e5.png" alt="mpl_bug_wo_tight_layout" style="max-width: 100%;"></a></p>
<p dir="auto">Matplotlib should <del>either raise a proper error</del> raise a proper warning, or plot the histograms in the proper order.</p>
<p dir="auto"><strong>Matplotlib version</strong></p>
<p dir="auto">Matplotlib 2.0.0</p>