Create Contour Plot from Pandas Groupby Dataframe

Question

I have following Pandas Dataframe:

In [66]: hdf.size()
Out[66]:
a           b
0           0.0          21004
            0.1         119903
            0.2               


        

Answer 1

Welcome to SO.

It looks quite clear that for each of your 'a' level, the numbers of 'b' levels are not the same, thus I will suggest the following solution:

In [44]:

print df #an example, you can get your dataframe in to this by rest_index()
    a  b     value
0   0  1  0.336885
1   0  2  0.276750
2   0  3  0.796488
3   1  1  0.156050
4   1  2  0.401942
5   1  3  0.252651
6   2  1  0.861911
7   2  2  0.914803
8   2  3  0.869331
9   3  1  0.284757
10  3  2  0.488330

[11 rows x 3 columns]
In [45]:
#notice that you will have some 'NAN' values
df=df.pivot('a', 'b', 'value')
In [46]:

X=df.columns.values
Y=df.index.values
Z=df.values
x,y=np.meshgrid(X, Y)
plt.contourf(x, y, Z) #the NAN will be plotted as white spaces
Out[46]: