MathGroup Archive 2007

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Exclusions inconsistancy

  • To: mathgroup at
  • Subject: [mg79727] Re: Exclusions inconsistancy
  • From: "David Park" <djmpark at>
  • Date: Thu, 2 Aug 2007 04:02:55 -0400 (EDT)
  • References: <f8pj9l$269$>

The documentation doesn't say that Exclusions and ExclusionsStyle plots 
asymptotes. It only plots excluded regions. In the odd cases you cite the 
excluded region defines a line but in the even cases it only defines a point 
at infinity.

It would be nice to know the actual algorithm used, especially for 
2-dimensional exclusion regions. For the plots you cite it probably draws a 
line between the left and right limits.

David Park
djmpark at

"Ken Levasseur" <klevasseur at> wrote in message 
news:f8pj9l$269$1 at
>A student just pointed out to me that the asymptote at x=1 is drawn
> in the following plot only when k is odd.  For even values, no
> asymptote appears.
> Plot[1/(x - 1)^k, {x, -5, 5}, PlotRange -> {{-5, 5}, {-5, 5}},
>    Exclusions -> {x - 1 == 0}, ExclusionsStyle -> {{Thick, Red}}]
> This appears to generalize to other examples like Tan[x]^k.
> Anyone know why?
> Ken Levasseur
> Mathematical Sciences
> UMass Lowell

  • Prev by Date: Re: Mathematica 6.0 math.exe question
  • Next by Date: Re: removing those annoying $$$$'s from local variables names?
  • Previous by thread: Exclusions inconsistancy
  • Next by thread: Re: Differential eqation: command set up