Geoffrey.Coram wrote: Hi all > expr_tol also! > In this case, I don't know what a zero tolerance would mean. > > Are we going to say that only positive tolerances are allowed > (since we haven't defined behavior for zero), or are we going > to say "non-negative" and just leave out a description of > what zero means? Or say the behavior for zero is undefined > and/or simulator dependent? I agree for expr_tol, but there is a bit of a difference between the expression and time tolerances. The expression is effectively continuous (down to 1 unit in the last place [ULP], about 1 part in 1e17). This governs the effective minimum meaningful expression tolerance. The time is discrete, with a simulator-dependent step size (and equally dependent minimum step size). So for the time tolerance, the smallest meaningful value is this minimum step size. In either case, I think that if a value of 0 is to be accepted, should behave the same as if the tolerance were ommitted. Now that cross/above/timer can have null arguments, I don't see that there is any real benefit, other than a lazy way of saying "give me the smallest possible tolerance". Regards Paul Floyd -- Dr Paul Floyd Mentor Graphics Corporation -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.Received on Fri Jul 25 09:02:48 2008
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