Re: A plot of Sign[x]
- To: mathgroup at smc.vnet.net
- Subject: [mg94112] Re: A plot of Sign[x]
- From: "sjoerd.c.devries at gmail.com" <sjoerd.c.devries at gmail.com>
- Date: Fri, 5 Dec 2008 05:30:34 -0500 (EST)
- References: <gh8hjr$r0h$1@smc.vnet.net>
I don't think you're doing things wrong here. I assume it has to do
with the numerical precission with which Sign works. The manual
states: "For exact numeric quantities, Sign internally uses numerical
approximations to establish its result. This process can be affected
by the setting of the global variable $MaxExtraPrecision. " Increasing
$MaxExtraPrecision doesn't work though.
If I were you I'd use Mesh->All
Cheers -- Sjoerd
On Dec 4, 2:14 pm, "Bert Aerts (rm X)" <bert.aer... at advalvas.beX>
wrote:
> I tried to plot the Sign function, making clear that Sign[0]=0 by typin=
g
> Plot[Sign[x], {x, -5, 5}, Mesh -> 51, PlotRange -> All]
> Making Mesh an odd value shows x=0.
>
> But the point at x=0 is being plot as 0.5 in stead of zero.
>
> What am I doing wrong?
>
> Mathematica 6.0.3 Linux x86_64