Allow for some margin at the top and bottom of plot windows in OMEdit

[Francesco Casella]

Consider the attached simple test case, where y is a PWM signal whose range is 0-1 (off/on). If I plot y, I obtain the screenshot attached in Fig1. Finding out when y is on and when it is off is quite tricky. I can switch the grid off, which improves the situation when y = 1, but not when y = 0, because the (flat) y curve is superimposed to the time axis, and the only way to tell them apart is color, which can be tricky, particularly if you are color blind (I'm not, but I know people who are).

Now, try zooming in on any time interval (say, 15 to 25), in a way that shows both 0 and 1 values. I've been dealing with PWM systems recently, and I can tell you this is really annoying...

I would suggest that the autoscale settings are such that a small margin (e.g. 3% of the whole range) is left blank at the top at the bottom of the diagram. In this case, the Fit in View range should be -0.03 - 1.03. The result with grid turned off is attached in Fig2, and is obviously much clearer what the PWM signal is doing. Furthermore, zooming in is much easier, because it is now possible to select an area that includes the 0-1 interval with some margin.

[Adeel Asghar]

Done in f96d9de/OpenModelica.