It's not clear to me what information the graph is trying to convey. Being an EA there isn't any doc info available.
See this other recent thread where one of the questions was similar.
I don't know the source of that info. It might be V$LOG or V$LOG_HISTORY.
The typical log switch interval might be in minutes or hours. But archived or inactive logs aren't going to change at all.
And the REDO logs are usually multiplexed in multiple groups.
What INFO in particular were you expecting the graph to show?
Well, the graph shows the number auf active and inactive redo logs. So far so good. I can see the numbers and they seem to be plausible. What is somewhat confusing is the ticks in the diagram showing up for 0, 0.5, 1, 1.5 and so on. Since the number of active redo logs is always an integer, showing ticks for 0.5 and 1.5 does not make any sense.
That is my issue with this diagram. The redo log groups normally are in sync with each other so there is no need to display them separately. (IMHO)
As for the log switch interval I'm expecting it to be shown as mintues but it is shown as days:
I hope that clarifies my complaints a bit.