I have a table such as

```
Group Family Nb 
1     A      15
2     B      20
3     A      2
3     B      1
3     C      1
4     D      10
4     A      5
5     B      1
5     D      1

```

And I would like to transform that dataframe such that I have each unique `Family` element in columns, and for each `Group`, the frequency of the `Nb` element, I should then get :

```
 Group  A    B    C    D    E  F
 1      1    0    0    0    0  0
 2      0    1    0    0    0  0
 3      0.5  0.25 0.25 0    0  0
 4      0.33 0    0    0.67 0  0
 5      0    0.5  0    0.5  0  0

```

Here is the dput format of the tabel if it can helps :

```
Family = c("A", "B", "A", "B", "C", "D", "A", "B", "D"), 
    Nb = c(15L, 20L, 2L, 1L, 1L, 10L, 5L, 1L, 1L)), class = "data.frame", row.names = c(NA, 
-9L))

```