title: specific location for inset axes
body: <p>I want to create a set of axes to form an inset at a specific location in the parent set of axes.  It is therefore not appropriate to just use the parameter <code>loc=1,2,3</code> in the <code>inset_axes</code> as shown here:</p>
  
  <pre><code>inset_axes = inset_axes(parent_axes,
                      width="30%", # width = 30% of parent_bbox
                      height=1., # height : 1 inch
                      loc=3)
  </code></pre>
  
  <p>However, I would like something close to this.  And the answers <a href="https://stackoverflow.com/questions/14589600/matplotlib-insets-in-subplots">here</a> and <a href="https://stackoverflow.com/questions/19335900/inset-axes-anchored-to-specific-points-in-data-coordinates">here</a> seem to be answers to questions slightly more complicated than mine.  </p>
  
  <p>So, the question is is there a parameter that I can replace in the above code that will allow custom locations of the inset axes within the parent axes?  I've tried to use the <code>bbox_to_anchor</code> but do not understand it's specification or behavior from the <a href="https://matplotlib.org/mpl_toolkits/axes_grid/api/inset_locator_api.html" rel="noreferrer">documentation</a>.  Specifically I've tried:</p>
  
  <pre><code> inset_axes = inset_axes(parent_axes,
                          width="30%", # width = 30% of parent_bbox
                          height=1., # height : 1 inch
                          bbox_to_anchor=(0.4,0.1))
  </code></pre>
  
  <p>to try to get the anchor for the left and bottom of the inset to be at 40% and 10% of the x and y axis respectively.  Or, I tried to put it in absolute coordinates:</p>
  
  <pre><code>inset_axes = inset_axes(parent_axes,
                              width="30%", # width = 30% of parent_bbox
                              height=1., # height : 1 inch
                              bbox_to_anchor=(-4,-100))
  </code></pre>
  
  <p>Neither of these worked correctly and gave me a warning that I couldn't interpret. </p>
  
  <p>More generally, it seems like <code>loc</code> is a pretty standard parameter in many functions belonging to <code>matplotlib</code>, so, is there a general solution to this problem that can be used anywhere?  It seems like that's what <code>bbox_to_anchor</code> is but again, I can't figure out how to use it correctly. </p>