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<p>Hello.</p>
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<p>For point 1, just put <br>
</p>
<p><b>plt.xticks(np.linspace(-4,5,9,endpoint=False))</b><b><br>
</b><b>plt.yticks(np.linspace(-1,2,7,endpoint=True))</b><br>
</p>
<p>before saving the picture does the job on my computer.</p>
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<p>For point 2, you have to understand that in your code you work
globally and locally on a subplot. In your case, the use of a
subplot is not necessary.<br>
</p>
<p><br>
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<p>See the little simplified version of your code joined to this
message which also hides the axis.</p>
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<p>PS 1: you should produce MWEs which are short codes showing one
identified problem.</p>
<p><br>
</p>
<p>PS 2: I hope that "les éditions Bordas" will cite the use of
matplotlib. ;-) <br>
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<pre class="moz-signature" cols="72">--
Christophe BAL
Enseignant Agrégé de Mathématiques
Programmeur Python Amateur</pre>
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