scipy.spatial.distance.

is_valid_y#

scipy.spatial.distance.is_valid_y(y, warning=False, throw=False, name=None)[source]#

Return True if the input array is a valid condensed distance matrix.

Condensed distance matrices must be 1-dimensional numpy arrays. Their length must be a binomial coefficient \({n \choose 2}\) for some positive integer n.

Parameters:

yarray_like: The condensed distance matrix.
warningbool, optional: Invokes a warning if the variable passed is not a valid condensed distance matrix. The warning message explains why the distance matrix is not valid. name is used when referencing the offending variable.
throwbool, optional: Throws an exception if the variable passed is not a valid condensed distance matrix.
namebool, optional: Used when referencing the offending variable in the warning or exception message.

Returns:

bool: True if the input array is a valid condensed distance matrix, False otherwise.

Examples

>>> from scipy.spatial.distance import is_valid_y

This vector is a valid condensed distance matrix. The length is 6, which corresponds to n = 4, since 4*(4 - 1)/2 is 6.

>>> v = [1.0, 1.2, 1.0, 0.5, 1.3, 0.9]
>>> is_valid_y(v)
True

An input vector with length, say, 7, is not a valid condensed distance matrix.

>>> is_valid_y([1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7])
False