On Friday 14 December 2012 23:54:06 Kent A. Reed did opine: > On 12/14/2012 10:40 PM, Peter C. Wallace wrote: > > On Fri, 14 Dec 2012, Kent A. Reed wrote: > >> On 12/14/2012 9:57 PM, Gene Heskett wrote: > >>> Greetings; > >>> > >>> I never got far enough in math to know what a 'derivative' is. Does > >>> anyone have a URL where I could learn a bit about this function? > >>> > >>> Thanks. > >>> > >>> Cheers, Gene > >> > >> Actually, the wikipedia article isn't bad: > >> http://en.wikipedia.org/wiki/Derivative > >> > >> If it gets too mathematical too quickly, just remember the geometric > >> interpretation: for a smooth continuous curve represented by a > >> function f(x), the slope of the curve at a point x=p is the > >> derivative of the function df/dx evaluated at x=p (ignoring all the > >> messy bits that require the mathematics to explain). > >> > >> Regards, > >> Kent > > > > And d/dt specifically: > > > > http://en.wikipedia.org/wiki/Time_derivative > > > > > > Peter Wallace > > Thanks, Peter, and sorry, Gene. By the time I checked wikipedia I'd > forgotten you asked about ddt specifically. > > For time derivatives, the first derivative (slope) of a function is > commonly called velocity (aka time rate of change) and the second > derivative is acceleration. > > Regards, > Kent
Thanks Kent. From this, it appears it would not do what needs to be done. So we can drop this trail off the map, its been explored to a dead end. What I think I need is a compression curve, so the top 50% of input is only a 10% range of the output, probably between the pid.output and pwmgen.value in. Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) My web page: <http://coyoteden.dyndns-free.com:85/gene> is up! Windows 98: New look, same multicrashing. I was taught to respect my elders, but its getting harder and harder to find any... ------------------------------------------------------------------------------ LogMeIn Rescue: Anywhere, Anytime Remote support for IT. Free Trial Remotely access PCs and mobile devices and provide instant support Improve your efficiency, and focus on delivering more value-add services Discover what IT Professionals Know. Rescue delivers http://p.sf.net/sfu/logmein_12329d2d _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
