<div dir="ltr">In the following cookbook example:<br><div><br><a href="http://yt-project.org/doc/cookbook/simple_plots.html#profiles-with-variance-values">http://yt-project.org/doc/cookbook/simple_plots.html#profiles-with-variance-values</a><br><br></div><div>the variance along the profile is extracted:<br><span class="gmail-n"><br>variance</span> <span class="gmail-o">=</span> <span class="gmail-n">prof</span><span class="gmail-o">.</span><span class="gmail-n">variance</span><span class="gmail-p">[</span><span class="gmail-s">'gas'</span><span class="gmail-p">,</span> <span class="gmail-s">'velocity_magnitude'</span><span class="gmail-p">]</span><span class="gmail-o">.</span><span class="gmail-n">value<br><br></span></div><div><span class="gmail-n">but is then labelled as the standard deviation when the plot is created:</span><span class="gmail-n"><br><br>plt</span><span class="gmail-o">.</span><span class="gmail-n">loglog</span><span class="gmail-p">(</span><span class="gmail-n">radius</span><span class="gmail-p">,</span> <span class="gmail-n">variance</span><span class="gmail-p">,</span> <span class="gmail-n">label</span><span class="gmail-o">=</span><span class="gmail-s">'Standard Deviation'</span><span class="gmail-p">)</span><br><br></div><div>So, does "prof.variance" return the standard deviation and not the variance?  Or, is the plot mislabelled?  Should the plot instead be:<br><br><span class="gmail-n">plt</span><span class="gmail-o">.</span><span class="gmail-n">loglog</span><span class="gmail-p">(</span><span class="gmail-n">radius</span><span class="gmail-p">,</span> <span class="gmail-n">np.sqrt(variance</span><span class="gmail-p">),</span> <span class="gmail-n">label</span><span class="gmail-o">=</span><span class="gmail-s">'Standard Deviation'</span><span class="gmail-p">)</span><br><br></div></div>