Less rigid '--rigid' option

[rrdtool@…]

I'd like to see an option that would allow autoscaling when the displayed values were all below upper-limit (or above lower-limit), but would function like rigid when the limit was reached. For example, suppose that upper-limit was 100, and we had three datapoints at 5, 9, 12. The Y axis would go from 0 to 15. If we added three more points at 20, 27, 35, the Y axis would go to 40. Add three more points at 50, 90, 120, and the Y axis would go up to 100, and the final datapoint would be "off the chart".

I'd like this feature because I have several data feeds that have occasional large spikes. If I don't put in a --rigid limit, a single datapoint that's 10x the rest of the data will get me a graph with a bumpy line across the bottom and one big spike. If I put in a --rigid limit, I can get a decent compromise for the whole dataset, but then if I look at a period that has no spike, the Y axis goes to a value that's far too high for the displayed data.