In [1]:

    

import numpy as np
import pandas as pd
from altair import api, html


def pairgrid_transform(data, rows, cols=None):
    """
    Transform a dataframe to allow vega to produce a PairGrid
    
    """
    if cols is None:
        cols = rows
      
    M1 = len(rows)
    M2 = len(cols)
    N = len(data)
    
    data = pd.concat(M1 * M2 * [data])
    i = np.arange(N * M1 * M2)
    irow = np.arange(N * M1 * M2) // N % M1
    icol = np.arange(N * M1 * M2) // N // M1
    
    data['x'] = data[cols].values[i, icol]
    data['y'] = data[rows].values[i, irow]
    data['row'] = rows.values[irow]
    data['col'] = cols.values[icol]
    
    return data


    

In [2]:

    

import seaborn as sns
iris = sns.load_dataset('iris')
iris.head()


    

    
Out[2]:






  

    

      

      
sepal_length
      
sepal_width
      
petal_length
      
petal_width
      
species
    
  
  

    

      
0
      
5.1
      
3.5
      
1.4
      
0.2
      
setosa
    
    

      
1
      
4.9
      
3.0
      
1.4
      
0.2
      
setosa
    
    

      
2
      
4.7
      
3.2
      
1.3
      
0.2
      
setosa
    
    

      
3
      
4.6
      
3.1
      
1.5
      
0.2
      
setosa
    
    

      
4
      
5.0
      
3.6
      
1.4
      
0.2
      
setosa
    
  

In [3]:

    

data = pairgrid_transform(iris, iris.columns[:4])
data.head()


    

    
Out[3]:






  

    

      

      
sepal_length
      
sepal_width
      
petal_length
      
petal_width
      
species
      
x
      
y
      
row
      
col
    
  
  

    

      
0
      
5.1
      
3.5
      
1.4
      
0.2
      
setosa
      
5.1
      
5.1
      
sepal_length
      
sepal_length
    
    

      
1
      
4.9
      
3.0
      
1.4
      
0.2
      
setosa
      
4.9
      
4.9
      
sepal_length
      
sepal_length
    
    

      
2
      
4.7
      
3.2
      
1.3
      
0.2
      
setosa
      
4.7
      
4.7
      
sepal_length
      
sepal_length
    
    

      
3
      
4.6
      
3.1
      
1.5
      
0.2
      
setosa
      
4.6
      
4.6
      
sepal_length
      
sepal_length
    
    

      
4
      
5.0
      
3.6
      
1.4
      
0.2
      
setosa
      
5.0
      
5.0
      
sepal_length
      
sepal_length
    
  

In [4]:

    

from IPython.display import HTML

spec = api.Viz(data).encode(x='x', y='y', row='row', col='col', color='species').point()
html_out = html.render(spec)
HTML(html_out)


    

    




/Users/jakevdp/anaconda/envs/py3k/lib/python3.3/site-packages/pandas/core/internals.py:956: FutureWarning: comparison to `None` will result in an elementwise object comparison in the future.
  return self._try_coerce_result(func(values, other))






    
Out[4]: