AFAIK - no.

Volatile would be of no use. It only works within a user defined
Function which, when volatile, will recalculate every time the sheet
caclulates - or, if not volatile, will only calculate if cells to
which the formula refers are changed.

I can only sugest a macro which checks if columns are hidden or not
and changes a chart reference array accordingly. You seem to have done
this anyway. But you still have to figure out how to run it. I suppose
a simple button if all else fails.

Regards
BrianB
=============================================

"Jerry W. Lewis" wrote in message ...
Is there any event that would detect a user hiding or unhiding columns?

I have a graph that plots data together with some computed quantities.
I want the computed quantities to reflect only the data that is visible
on the graph (from columns that are not hidden). I wrote an IsVisible()
function to make the computations use only the visible data, but
hiding/unhiding columns does not trigger a recalculation, even if
IsVisible() is declared Volatile.

Jerry