# Measure

A “measurement region” is a user-specified {volume in 3D; area in 2D} within which a number of quantities in a PFC model are measured. Upon request, via the measure list or measure dump commands, for instance, or via FISH, any of these quantities may be obtained. Measurement regions return average values computed over objects that lie in or intersect the measurement region. The quantities available for measurement include coordination number, porosity, sliding fraction, stress, and strain rate. A measurement region is always a {sphere in 3D; circular disk in 2D}.

Measurement regions are created and defined by the measure create command, modified with the measure modify command, and the computed responses can be monitored using the measure history command. Measured quantities can also be accessed via FISH.