I saw a previous post with this same basic question back in 2005 but
it doesn’t look like anyone really answered the question of what the
max is.  I also found it (empirically) to be about 1.1. billion but I
don’t feel right hard coding an empirically found number.
In my situation I’m writing a program to plot time based data.  The
user has the option of auto-scaling or manually scaling the Y axis.  I
force max to always be greater than min but there are many legitimate
situations where min and max are very very close in some of the data
and then when they shift the view by a few minutes it’s very large
e.g. a device under vacuum at around 1e-10 Torr scale and then
suddenly jumping to atmosphere at ~760 Torr.  So in this situation I
basically just want to not plot the data since it’s way outside the
range.  But I just want to know what the cutoff should be when my
scaling is in pixels?