Resolving timeline scaling issues
If you manually adjust your timeline's scale settings, you may occasionally see the following notice:
Your timeline cannot be viewed at this scale
To understand why this happens, imagine a timeline with a single event that spans one year: Jan 1, 2017 through Dec 31, 2017:
By default, Preceden will automatically determine that months is the best possible scale to view this timeline. When viewed at this scale, there are 14 time periods displayed on the timeline: 12 for the event, plus one on both side for some padding.
But what would happen if you manually update the scale and set it to days? Now instead of 14 time periods, Preceden would have to display 365 plus two on each side for 367 total:
There are so many time periods that the timeline winds up looking squashed and you can't read any of the axis labels.
Rather than support this, Preceden identifies these situations and displays the " Your timeline cannot be viewed at this scale" notice letting you know that something is amiss.
Similarly, if instead of selecting days you select a scale of 50K years, Preceden also runs into trouble, but instead of there being too many time periods there wind up being too few:
Preceden also catches these situations and displays the "Your timeline cannot be viewed at this scale" notice.
Resolving scale issues
There are a few things you can try if you see this notice:
1) Click the Have Preceden determine the best scale link below the scale notice.
This will update your timeline to automatically calculate the best scale which in most situations will fix the issue.
2) Select the Automatically calculate the date range setting instead of manually setting a start and end date
Combined with Preceden's ability to automatically figure out the best scale, this will ensure the content on your timeline is displayed properly.
3) Uncheck the Display a vertical line on today's date setting if you have that setting turned on
This can cause issues if you've manually set a date range for your timeline where the time period you set is far from today's date. For example, if you have events that span 1990 through 1991, set the scale to quarters, but check the display current date setting, then instead of your timeline spanning two years it now spans more than 25. Viewing 25 years worth of events a quarter scale would result in over 100 time periods, which Preceden doesn't support.
In rare cases even with automatic scaling and date ranges your timeline's content won't be able to be displayed. I've only seen this in cases where the events on the timeline span several hundred thousand years and even in most of those cases Preceden is able to display the timeline without issues.
If you run in a situation where you're always seeing the " Your timeline cannot be viewed at this scale" notice no matter what, drop me an email at firstname.lastname@example.org and I'd be happy to take a look. Similarly, if you believe your timeline should be able to be viewed at a certain scale but it isn't working, I can take a look to figure out what the cause is.