title: Pandas dataframe errorbar plots separated by category
body: <p>So I've tried <code>seaborn</code> and <code>pandas</code> native plotting features and feel like I'm relegated to using pure <code>matplotlib</code> which is a disappointment but this is the problem I currently have.</p>
  
  <p>I have a <code>pandas</code> data frame that has x-values in time, y-values in magnitude, and custom error values in a column called uncertainty. I also have a column called Filters. For each filter, I want to plot essentially an error bar plot with <strong>x=time, y=magnitude, yerr = uncertainty</strong>. Here is a sample data (since the real data is proprietary):</p>
  
  <pre><code>Image   Filter    Time  Magnitude   Uncertainty
  File1   1 micron    0   12.1    0.008
  File2   1.5 micron  0   13.4    0.01
  File3   1 micron    1   12.9    0.01
  File4   1.5 micron  1   13.8    0.013
  File5   1 micron    2   14.2    0.014
  File6   1.5 micron  2   14.66   0.0155
  File7   1 micron    3   15.12   0.017
  File8   1.5 micron  3   15.58   0.0185
  File9   1 micron    4   16.04   0.02
  File10  1.5 micron  4   16.5    0.0215
  File11  1 micron    5   16.96   0.023
  File12  1.5 micron  5   17.42   0.0245
  File13  1 micron    6   17.88   0.026
  File14  1.5 micron  6   18.34   0.0275
  File15  1 micron    7   18.8    0.029
  File16  1.5 micron  7   19.26   0.0305
  File17  1 micron    8   19.72   0.032
  File18  1.5 micron  8   20.18   0.0335
  File19  1 micron    9   20.64   0.035
  File20  1.5 micron  9   21.1    0.0365
  </code></pre>
  
  <p>So on a single plot, I would like a series of points with errorbars (based on the uncertainty column) corresponding to that filter (either 1 micron or 1.5 micron).</p>
  
  <p>If I do this in <code>seaborn</code> I get the following:</p>
  
  <p><a href="https://i.stack.imgur.com/o8vJ6.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/o8vJ6.png" alt="Seaborn&#39;s attempt at doing a plot"></a></p>
  
  <p>I cannot do a map with errorbar (as is commented in the line above) because it claims: </p>
  
  <blockquote>
    <p>"ValueError: yerr must be a scalar, the same dimensions as y, or 2xN."</p>
  </blockquote>
  
  <p>If I try this in <code>pandas</code> directly, I get the following:</p>
  
  <p><a href="https://i.stack.imgur.com/mUC96.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/mUC96.png" alt="Pandas attempt at doing this"></a></p>
  
  <p>Neither of these is what I want. I thought <code>pandas</code> and <code>seaborn</code> were supposed to alleviate all these issues and make it simpler and easier to do this sort of work without having to do contrived nonsense like reading it into <code>numpy</code> genfromtxt, sorting by filter, etc.</p>