Calculate
The calculate toggle determines whether the skew curve updates with changes in
the input lines. The input lines are, of course, made up of options
’ implied volatilities over the range of strikes. When you define a curve, the
calculate field is on by default. However, when you save a skew curve and
recall it for editing or application, the calculation field is off by default.
The reason for this subtlety is that the skew curve shape should remain static
when it is applied to an options market. You can, of course, recall a skew for
editing and turn the calculate toggle on.