title: Vary marker sizes proportional to the values in a column for pandas line-plots with markers
body: <p>I have a pandas dataframe from which I need to plot a line plot with markers. For this purpose, I convert the dataframe into a pivot table where <code>index= "Distance", columns= "system", values= "fscore"</code>. With the <code>plot</code> method as used in the code snippet below, I can get a line plot as shown below. However, how exactly can I vary the marker size based on the values in the <code>lenth</code> column (or a normalised score of the values in the <code>lenth</code> column)?</p>
  
  <p><a href="https://i.stack.imgur.com/m7WKY.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/m7WKY.png" alt="enter image description here"></a></p>
  
  <p>Code snippet:</p>
  
  <pre class="lang-py prettyprint-override"><code>plotPD = df.pivot(index="Distance", columns="system", values="fscore").fillna(0)
  ax = plotPD.plot(
      marker="H",
      title="plotTitle",
      xticks=(range(0, len(plotPD.index) + 2, 2)),
      yticks=np.arange(0, 1.1, 0.1),
  )
  ax.set_xlabel(plotPD.index.name, fontsize=14)
  </code></pre>
  
  <p>The original dataframe <code>distPD</code></p>
  
  <pre><code>    system  Distance  lenth  summ    fscore
  0      L2S        12     45    31  0.688889
  1      L2S         9     84    52  0.619048
  2      L2S         1   1685  1471  0.872997
  3      L2S         2    578   403  0.697232
  4      L2S        13     47    30  0.638298
  279  BiAFF        17      9     8  0.888889
  280  BiAFF        19      7     5  0.714286
  281  BiAFF        21      5     5  1.000000
  282  BiAFF        20      4     4  1.000000
  283  BiAFF        26      2     2  1.000000
  </code></pre>