A chebychev distance measure, based on the maximum of the absolute distances across all dimensions.
A measure that uses the euclidean squared distance which is faster than the euclidean distance as the square root does not need to be taken.
An 'inverted' chebychev distance measure, based on the *minimum* of the absolute distances across all dimensions.
An 'inverted' chebychev distance measure, based on the *minimum* of the absolute distances across all dimensions. This is, strictly speaking, only a semi metric.