title: Pygraphviz- Warning: Overlap value "prism" unsupported - ignored warnings.warn(b"".join(errors).decode(self.encoding), RuntimeWarning)
body: <p>I am new to Graphviz, and I am trying a large graph with 7315 edges using the following code.</p>
  <pre><code>import pandas as pd
  import pygraphviz as pgv
  g = pgv.AGraph()
  
  ds = pd.read_csv(&quot;G:\cit-Patents_7315_1037462.txt&quot;,header=None)
  
  ds.rename(columns={0:'col1'},inplace = True)
  ds.rename(columns={1:'col2'},inplace = True)
  
  for index, row in ds.iterrows():
      g.add_edge(str(row[&quot;col1&quot;]), str(row[&quot;col2&quot;]))
  g.layout(prog='fdp')
  
  g.draw('7315.svg')
  </code></pre>
  <p>When g.layout() is called, the following warnings show up.</p>
  <pre><code>c:\users\new\appdata\local\programs\python\python39\lib\site-packages\pygraphviz\agraph.py:1390: RuntimeWarning: Warning: Overlap value &quot;prism&quot; unsupported - ignored
  Warning: Overlap value &quot;prism&quot; unsupported - ignored
  Warning: Overlap value &quot;prism&quot; unsupported - ignored
  Warning: Overlap value &quot;prism&quot; unsupported - ignored
  Warning: Overlap value &quot;prism&quot; unsupported - ignored
  Warning: Overlap value &quot;prism&quot; unsupported - ignored
  Warning: Overlap value &quot;prism&quot; unsupported - ignored
  
    warnings.warn(b&quot;&quot;.join(errors).decode(self.encoding), RuntimeWarning)
  </code></pre>
  <p>I am stuck here and could not understand how to resolve the problem.
  I appreciate any help provided.. Thanks in advance!!</p>