Re: machine precision number plot fixed in V6?

*To*: mathgroup at smc.vnet.net*Subject*: [mg83076] Re: machine precision number plot fixed in V6?*From*: "David Park" <djmpark at comcast.net>*Date*: Fri, 9 Nov 2007 05:21:07 -0500 (EST)*References*: <fgurjm$rh4$1@smc.vnet.net>

In Version 6 you can specify a WorkingPrecision option in graphics statements. I believe that this replaces the need for Ted's PrecisionPlot package (which might still be needed for pre Version 6.) -- David Park djmpark at comcast.net http://home.comcast.net/~djmpark/ <congruentialuminaire at yahoo.com> wrote in message news:fgurjm$rh4$1 at smc.vnet.net... > Hello Mathematica UG: > > I was doing some work with the PrecisionPlot package (http:// > library.wolfram.com/infocenter/MathSource/715/) > > When I ran it under V6, no output was emitted. So I looked again at > the documentation provided by Ted Ersek. Even though it is 8 years > old, it contains the following function and plot which does not work > correctly as recently as V5. > > In V6, the invocation with SetPrecision works and emits a smooth plot > (presumably eliminating the need for this package). Here are the lines > of code. > > ----------------------------------------------------------- > (* a function that does not plot well with machine-precision numbers > *) > f2[x_] = ArcSec[x] - Normal[Series[TrigToExp[ArcSec[x]], {x, \ > [Infinity], 7}]] > > (* a jagged plot results under V5 and V6 *) > Plot[f2[t], {t, 25, 40}] > > (* a smooth plot results only under V6 *) > Plot[f2[SetPrecision[t, 17]], {t, 25, 40}] > ------------------------------------------------------------ > > If there is a simple explanation for what was fixed in V6 to make this > work, I am interested to know. > > TIA. > > Regards..Roger > >