Do you mean if you input it manually or if it's spell based? It should pick up changes once you toggle your auto-attack (I could have it update more often, e.g. upon every CA you cast, but that would cost a bit more performance of course). I suppose some spells may not be reflected correctly by the DynamicData, at least it used to be like that. If all the data is correct but it shows the wrong numbers it's a bug in my code.
However, if for some reason it does not automatically recalculate there is a button in the lower left corner (shows on mouse over) to force it to recalculate.