Subject: Clarification, please, on monotonicity

From: Bob Ward <[email-masked]>
Date: Tue, 26 Apr 94 08:29:11 -0500

All -

We have had several discussions of monotonic and non-monotonic behaviour of 
drivers, but there is a point which remains ambiguous in my mind.  When we
speak of monotonicity, do we mean strictly rising ( or falling ) waveforms, 
or do we accept non-decreasing ( non-increasing ) waveforms as monotonic?
That is would a waveform be considered monotonic if it rose for a while,
flattened out to a number of equal values and then rose again?  The question really is
does the derivative have to be always of  the same sign, or is a derivative that
has a zero region acceptable as a definition of monotonic?  According to the
strict mathematical definition, the derivative must be of the same sign and non-
zero over the interval of interest.  But it seems to me that we are more 
interested here in allowing the zero region of the derivative and so talking
about non_decreassing ( or non-increasing ).  Either can make a valid working
definition, but it makes a difference as I code a test for the condition as to
which we mean.

Clarification?  Comments?

Thanks,

 Bob             [email-masked]     or     [email-masked]

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From: [email-masked] (Jon Powell)
Date: Tue, 26 Apr 94 08:32:39 PDT

Non-monotonic

I always intened monotonic to mean no sign change or no
value change. What I am trying to avoid is un-stable configurations
caused by load lines that can intersect an IV curve at more than
one stable point. I think this can only happen with a complete sign
change. (Now I have to go get some graph paper.)

jonp