>>> from proves import proves_estables

>>> dades1 = [
...     [7.5, 8.2, 9.8, 9.9, 10.0, 10.1, 13.5, 14],
...     [9.0, 9.2, 9.5, 9.6, 9.7, 9.8, 10.0, 10.1],
...     [4.0, 5.0, 9.5, 9.6, 9.7, 9.8, 20.0, 22],
...     [8.0, 9.5, 9.7, 9.8, 10.0, 11.0]
... ]

>>> proves_estables(dades1, 2, 0.5)
[(0, 9.9, 0.4), (1, 9.7, 0.0), (3, 9.8, 0.1)]

>>> proves_estables(dades1, 2, 0.03)
[]

>>> proves_estables(dades1, 1, 0.1)
[(1, 9.6, 0.0), (3, 9.8, 0.1)]

>>> dades2 = [
...     [0, 0, 0, 0, 30, 30, 40, 40, 40],
...     [0, 0, 0, 0, 30, 30, 70, 70, 70],
...     [5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16],
...     [0, 0, 0, 0, 0, 0, 10, 10, 10, 10, 10, 50, 50, 50, 50],
...     [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20],
...     [2, 4, 6, 20, 22, 24, 26, 28, 60, 80],
...     [0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100],
...     [4, 4, 4, 4, 9, 9, 9, 30, 30, 30, 30, 30, 30]
... ]

>>> proves_estables(dades2, 3, 1.0)
[(0, 20.0, 0.0), (2, 10.5, 0.0), (4, 10.5, 0.0), (6, 50.0, 0.0), (7, 17.3, 0.1)]

>>> proves_estables(dades2, 4, 1.0)
[(1, 30.0, 0.0), (2, 10.5, 0.0), (4, 10.5, 0.0), (6, 50.0, 0.0), (7, 17.4, 0.2)]