title: Buffer for this type not yet supported when using rpy2 in jupyter notebook
body: <p>I have installed all the packages required for rpy2, I want to embed R code in the jupyter notebook to do the data visualization.</p>
  <p>But there's not much luck so far in my case, please point out which part I did wrong. Hope for a solution.</p>
  <pre><code># Import the libraries
  
  import pandas as pd
  import matplotlib.pyplot as plt
  import rpy2
  
  # Imports required from rpy2
  from rpy2.robjects import pandas2ri   
  pandas2ri.activate()
  %load_ext rpy2.ipython
  </code></pre>
  <pre><code>SheetA = pd.read_csv('C:\\Users\\test\\SheetA.csv')
  SheetA_header=['Grill Type', 'Pre-Heat Time (In Seconds)', 'Fuel Cost Per Meal ($)', 'Market Share (%)', 'Ease Of Use', 'Life Span (In Years)', 'Initial Investment ($)']
  SheetA=pd.read_csv(&quot;C:\\Users\\test\\SheetA.csv&quot;, header=None, skiprows=1, names=SheetA_header)
  SheetA = pd.DataFrame(SheetA)
  </code></pre>
  <pre><code>%%R -i SheetA
  
  library(ggplot2)
  
  ggplot(SheetA)
  
  D:\Anaconda\lib\site-packages\rpy2\ipython\rmagic.py in _(obj)
      147     if 'data.frame' in obj.rclass:
      148         # request to turn it to a pandas DataFrame
  --&gt; 149         res = converter.ri2py(obj)
      150     else:
      151         res = ro.sexpvector_to_ro(obj)
  
  D:\Anaconda\lib\functools.py in wrapper(*args, **kw)
      838                             '1 positional argument')
      839 
  --&gt; 840         return dispatch(args[0].__class__)(*args, **kw)
      841 
      842     funcname = getattr(func, '__name__', 'singledispatch function')
  
  D:\Anaconda\lib\site-packages\rpy2\robjects\pandas2ri.py in ri2py_listvector(obj)
      181 def ri2py_listvector(obj):
      182     if 'data.frame' in obj.rclass:
  --&gt; 183         res = ri2py(DataFrame(obj))
      184     else:
      185         res = numpy2ri.ri2py(obj)
  
  D:\Anaconda\lib\functools.py in wrapper(*args, **kw)
      838                             '1 positional argument')
      839 
  --&gt; 840         return dispatch(args[0].__class__)(*args, **kw)
      841 
      842     funcname = getattr(func, '__name__', 'singledispatch function')
  
  D:\Anaconda\lib\site-packages\rpy2\robjects\pandas2ri.py in ri2py_dataframe(obj)
      188 @ri2py.register(DataFrame)
      189 def ri2py_dataframe(obj):
  --&gt; 190     items = tuple((k, ri2py(v)) for k, v in obj.items())
      191     res = PandasDataFrame.from_items(items)
      192     return res
  
  D:\Anaconda\lib\site-packages\rpy2\robjects\pandas2ri.py in &lt;genexpr&gt;(.0)
      188 @ri2py.register(DataFrame)
      189 def ri2py_dataframe(obj):
  --&gt; 190     items = tuple((k, ri2py(v)) for k, v in obj.items())
      191     res = PandasDataFrame.from_items(items)
      192     return res
  
  D:\Anaconda\lib\functools.py in wrapper(*args, **kw)
      838                             '1 positional argument')
      839 
  --&gt; 840         return dispatch(args[0].__class__)(*args, **kw)
      841 
      842     funcname = getattr(func, '__name__', 'singledispatch function')
  
  D:\Anaconda\lib\site-packages\rpy2\robjects\pandas2ri.py in ri2py_vector(obj)
      137 @ri2py.register(SexpVector)
      138 def ri2py_vector(obj):
  --&gt; 139     res = numpy2ri.ri2py(obj)
      140     return res
      141 
  
  D:\Anaconda\lib\functools.py in wrapper(*args, **kw)
      838                             '1 positional argument')
      839 
  --&gt; 840         return dispatch(args[0].__class__)(*args, **kw)
      841 
      842     funcname = getattr(func, '__name__', 'singledispatch function')
  
  D:\Anaconda\lib\site-packages\rpy2\robjects\numpy2ri.py in ri2py_sexp(obj)
      157 def ri2py_sexp(obj):
      158     if (obj.typeof in _vectortypes) and (obj.typeof != VECSXP):
  --&gt; 159         res = numpy.asarray(obj)
      160     else:
      161         res = ro.default_converter.ri2py(obj)
  
  D:\Anaconda\lib\site-packages\numpy\core\_asarray.py in asarray(a, dtype, order)
       83 
       84     &quot;&quot;&quot;
  ---&gt; 85     return array(a, dtype, copy=False, order=order)
       86 
       87 
  
  ValueError: Buffer for this type not yet supported.
  </code></pre>
  <p>There's must be something wrong when processing dataframe to rpy2, only a guess.</p>