Arithmetic operators on a measure A
are only defined
in some cases. The arithmetic operator is effectively applied
to the value of A(W)
for every spatial domain W
.
If the result is a measure, then this operation is valid.
If A
is a measure (object of class "msr"
)
then the operations -A
and +A
are defined.
If A
and B
are measures with the same dimension
(i.e. both are scalar-valued, or both are k
-dimensional vector-valued)
then A + B
and A - B
are defined.
If A
is a measure and z
is a numeric value,
then A * z
and A / z
are defined,
and z * A
is defined.