The restriction function type depends upon the tensor type of field
. The following are the restriction functions 
:
Current value:
This function consists of the current value of
. This function can only be applied when 
is a scalar field. This is selected automatically, since
the values of the scalars are detected. Norm of vector:
This function computes the norm of the vector
. This function can only be applied when 
is a vector field. 
component of vector or tensor: 
This function extracts the 
component of a vector or a tensor.