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komm.DiscreteMemorylessSource

Discrete memoryless source (DMS). It is defined by an alphabet $\mathcal{X}$ and a probability mass function (pmf) $p_X$. Here, for simplicity, the alphabet is always taken as $\mathcal{X} = \{ 0, 1, \ldots, |\mathcal{X}| - 1 \}$. The pmf $p_X$ gives the probability of the source emitting the symbol $X = x$.

To invoke the source, call the object giving the number of symbols to be emitted as parameter (see example in the constructor below).

Attributes:

  • pmf (np.ndarray) –

    The source probability mass function $p_X$. The element in position $x \in \mathcal{X}$ must be equal to $p_X(x)$.

Examples:

>>> np.random.seed(42)
>>> dms = komm.DiscreteMemorylessSource([0.5, 0.4, 0.1])
>>> dms(10)
array([0, 2, 1, 1, 0, 0, 0, 1, 1, 1])

cardinality property

The cardinality $|\mathcal{X}|$ of the source alphabet.

entropy()

Returns the source entropy $\mathrm{H}(X)$. See komm.entropy for more details.

Parameters:

  • base (Optional[float | str]) –

    See komm.entropy. The default value is $2.0$.

Examples:

>>> dms = komm.DiscreteMemorylessSource([1/2, 1/4, 1/8, 1/8])
>>> dms.entropy()
1.75
>>> dms.entropy(base=4)
0.875