1. [scientific computation] Used of a data set that is grossly atypical of
normal expected input, especially one that exposes a weakness or bug in whatever
algorithm one is using. An algorithm that can be broken by pathological inputs
may still be useful if such inputs are very unlikely to occur in practice.
2. When used of test input, implies that it was purposefully engineered as a
worst case. The implication in both senses is that the data is spectacularly
ill-conditioned or that someone had to explicitly set out to break the algorithm
in order to come up with such a crazy example.
3. Also said of an unlikely collection of circumstances. "If the network is down
and comes up halfway through the execution of that command by root, the system
may just crash." "Yes, but that's a pathological case." Often used to dismiss
the case from discussion, with the implication that the consequences are
acceptable, since they will happen so infrequently (if at all) that it doesn't
seem worth going to the extra trouble to handle that case (see sense 1).
path coverage testing « pathname « pathname
pathological » Path Pascal » pathspec » pattern