RE: Re: Graphing Abnormalities of Functions

• To: mathgroup at smc.vnet.net
• Subject: [mg29560] RE: [mg29552] Re: Graphing Abnormalities of Functions
• From: "David Park" <djmp at earthlink.net>
• Date: Sun, 24 Jun 2001 22:10:17 -0400 (EDT)
• Sender: owner-wri-mathgroup at wolfram.com

```Ryan,

There is a somewhat simpler method than my first posting. Plot a white disk
to blank out the line and then draw the circle.

Needs["Graphics`Colors`"]

f[x_] := ((x^2) + x - 2)/(x - 1)

Plot[f[x], {x, 0, 5}, Epilog ->
{White, Disk[{1, 3}, 0.05], Black,
Circle[{1, 3}, 0.05]}, AspectRatio -> Automatic,
PlotRange -> {0, 7}, Axes -> True,
AxesLabel -> {x, y}, PlotLabel ->
"Function with Discontinuity", ImageSize -> 350];

David Park

> -----Original Message-----
> From: Ryan R. Rosario [mailto:rrosario11 at my-deja.com]
To: mathgroup at smc.vnet.net
> Sent: Sunday, June 24, 2001 2:01 AM
> To: mathgroup at smc.vnet.net
> Subject: [mg29560] [mg29552] Re: Graphing Abnormalities of Functions
>
>
> Hi-
>
> Thanks for the response :-)
>
> By a hole, I mean a removable discontinuity in a graph. For example,
> the function ((x^2) + x - 2)/(x - 1) is discontinuous because when
> x=1, the function is undefined. I learned that this is called a
> "hole." Perhaps I am using the wrong terminology. If so, silly me LOL
> :-)
>
> In textbooks, this discontinuity is indicated by displaying a hollow
> circle at the point of discontinuity (hole).
>
> Is there a way to tell Mathematica to draw this circle at the point of
> discontinuity rather than simply display a break in the graph?
>
> Thanks Again,
> Ryan
>

```

• Prev by Date: Re: Making a list
• Next by Date: Re: Re: Graphing Abnormalities of Functions
• Previous by thread: Re: Graphing Abnormalities of Functions
• Next by thread: Re: Re: Graphing Abnormalities of Functions