skbio.core.distance.randdm(num_objects, ids=None, constructor=None, random_fn=None)[source]

Generate a distance matrix populated with random distances.

Using the default random_fn, distances are randomly drawn from a uniform distribution over [0, 1).

Regardless of random_fn, the resulting distance matrix is guaranteed to be symmetric and hollow.


num_objects : int

The number of objects in the resulting distance matrix. For example, if num_objects is 3, a 3x3 distance matrix will be returned.

ids : sequence of str or None, optional

A sequence of strings to be used as IDs. len(ids) must be equal to num_objects. If not provided, IDs will be monotonically-increasing integers cast as strings (numbering starts at 1). For example, ('1', '2', '3').

constructor : type, optional

DissimilarityMatrix or subclass constructor to use when creating the random distance matrix. The returned distance matrix will be of this type. If None (the default), a DistanceMatrix instance will be returned.

random_fn : function, optional

Function to generate random values. random_fn must accept two arguments (number of rows and number of columns) and return a 2D numpy.ndarray of floats (or something that can be cast to float). If None (the default), numpy.random.rand will be used.



DissimilarityMatrix (or subclass) instance of random distances. Type depends on constructor.