Use operators to modify point attributes

Values may be modified arithmetically by using the following operators:

• attribute += value

• attribute -= value

• attribute *= value

• attribute /= value

This example changes all tags with a point source of X to have a zero that is 10 units less than its current value and increases the span to 110 percent of its current value:

@table pipoint
@mode edit
@select tag=*, pointsource=X
@modify zero-=10, span*=1.1
@endsection

modify specifications remain in effect until a table is changed. New modify specifications are added to previous specifications until data is processed. After this, new specifications replace previous ones.