is_valid_y — SciPy v1.15.2 Manual (original) (raw)

scipy.spatial.distance.

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