requires that the master node
must be in the average position of the slave nodes.The translational constraint requires that the master node
must be in the average position of the slave nodes.
where 
is the 
vector of translational
coordinates of the master node, n is the
number of slave nodes in the Interpolation element,
and 
is the vector of translational
coordinates of the ith slave node.
Therefore, the translational constraint is
