Using pandas, is it possible to compute a single cross-tabulation (or pivot table) containing values calculated from two different functions?
import pandas as pd
import numpy as np
c1 = np.repeat(['a','b'], [50, 50], axis=0)
c2 = list('xy'*50)
c3 = np.repeat(['G1','G2'], [50, 50], axis=0)
np.random.shuffle(c3)
c4=np.repeat([1,2], [50,50],axis=0)
np.random.shuffle(c4)
val = np.random.rand(100)
df = pd.DataFrame({'c1':c1, 'c2':c2, 'c3':c3, 'c4':c4, 'val':val})
frequencyTable = pd.crosstab([df.c1,df.c2],[df.c3,df.c4])
meanVal = pd.crosstab([df.c1,df.c2],[df.c3,df.c4],values=df.val,aggfunc=np.mean)
So, both the rows and the columns are the same in both tables, but what I'd really like is a table with both frequencies and mean values:
c3 G1 G2
c4 1 2 1 2
c1 c2 freq val freq val freq val freq val
a x 6 0.624931 5 0.582268 8 0.528231 6 0.362804
y 7 0.493890 8 0.465741 3 0.613126 7 0.312894
b x 9 0.488255 5 0.804015 6 0.722640 5 0.369480
y 6 0.462653 4 0.506791 5 0.583695 10 0.517954
You can give a list of functions:
pd.crosstab([df.c1,df.c2], [df.c3,df.c4], values=df.val, aggfunc=[len, np.mean])
If you want the table as shown in your question, you will have to rearrange the levels a bit:
In [42]: table = pd.crosstab([df.c1,df.c2], [df.c3,df.c4], values=df.val, aggfunc=[len, np.mean])
In [43]: table
Out[43]:
len mean
c3 G1 G2 G1 G2
c4 1 2 1 2 1 2 1 2
c1 c2
a x 4 6 8 7 0.303036 0.414474 0.624900 0.425234
y 5 5 8 7 0.543363 0.480419 0.583499 0.637657
b x 10 6 4 5 0.400279 0.436929 0.442924 0.287572
y 6 8 5 6 0.400427 0.623319 0.764506 0.408708
In [44]: table.reorder_levels([1, 2, 0], axis=1).sort_index(axis=1)
Out[44]:
c3 G1 G2
c4 1 2 1 2
len mean len mean len mean len mean
c1 c2
a x 4 0.303036 6 0.414474 8 0.624900 7 0.425234
y 5 0.543363 5 0.480419 8 0.583499 7 0.637657
b x 10 0.400279 6 0.436929 4 0.442924 5 0.287572
y 6 0.400427 8 0.623319 5 0.764506 6 0.408708