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Re: No Show

• To: mathgroup at smc.vnet.net
• Subject: [mg89222] Re: No Show
• From: Narasimham <mathma18 at hotmail.com>
• Date: Fri, 30 May 2008 02:55:18 -0400 (EDT)
• References: <g1bf08$mcv$1@smc.vnet.net> <200805260529.BAA09868@smc.vnet.net>

If this does not reappear next time for same commands and goes away ok
on re-boot, why bother?

On May 28, 1:50 pm, "Jose Luis Gomez" <jose.luis.go... at itesm.mx>
wrote:
> I was able to rotate the sphere many times without any problem
> "6.0 for Microsoft Windows (32-bit) (April 20, 2007)"
>
> Jose
> Mexico
>
> -----Mensaje original-----
> De: Syd Geraghty [mailto:sydgerag... at mac.com]
> Enviado el: Martes, 27 de Mayo de 2008 06:14 a.m.
> Para: mathgr... at smc.vnet.net
> Asunto:  Re: No Show
>
> Hi,
>
> This is a report to the Mathgroup and will also be reported as a bug
> to Wolfram support.
>
> I experienced very weird system behaviour evaluating the following
> code from Helen's post below:-
>
> > You might also want to set the BoxRatios.
>
> > bot = Plot3D[-Sqrt[1 - (x^2 + y^2)], {x, -1, 1}, {y, -1, 1}];
> > top = Plot3D[+Sqrt[1 - (x^2 + y^2)], {x, -1, 1}, {y, -1, 1}];
> > Show[top, bot, PlotRange -> Automatic, BoxRatios -> {1, 1, 1}]
>
> I would be interested if anyone else can reproduce the problem.
>
> When rotating the graphic output from Show above (A boxed sphere with
> 3D axes) I could generate what appears as a jumbled ray trace diagram
> for the image.
>
> I held the jumbled output and could copy and paste it. I thought I
> would paste it into iPhoto and post it on my website so as I could
> share the image with Mathgroup or WRI Bug support. Imagine my surprise
> when I opened iPhoto and as soon as I scrolled within that window I
> started to paint similar raytraced regions on my screen. At this point
> I suspected a hardware graphics IC or memory failure.
>
> However I rebooted the system and all seems well. I opened iPhoto and
> then Aperture and could scroll thousands of photos OK.
>
> I now suspect a Mathematica bug generated while doing the rotation.
>
> Of course it might still prove to be my system problem. However I can
> open the offending Mathematica notebook and still see the saved raytrace
> output (without re-evaluation which I avoided so I could send this
> email).
>
> My system info is below. Good luck tracking this behaviour WRI!
>
> Cheers ... Syd
>
> Syd Geraghty B.Sc, M.Sc.
>
> sydgerag... at mac.com
>
> My System
>
> Mathematica 6.0.2.1 for Mac OS X x86 (64 - bit) (March 13, 2008)
> MacOS X V 10.5.2
> MacBook Pro 2.33 Ghz Intel Core 2 Duo  2GB RAM
>
> On May 25, 2008, at 10:29 PM, Helen Read wrote:
>
> > Narasimham wrote:
> >> Why is the following plot, bot, (with - Sqrt) not Shown along with
> >> top?
>
> >> Why is it treated only as a plot skeleton, so no combining is
> >> possible?
>
> >> bot = Plot3D[-Sqrt[1 - (x^2 + y^2) ] , {x, -1, 1}, {y, -1, 1}]
> >> top = Plot3D[+Sqrt[1 - (x^2 + y^2) ] , {x, -1, 1}, {y, -1, 1}]
> >> Show[top, bot]
>
> > Oh, you are going to get a lot of replies to this. It was discussed at
> > length when v.6 was first released. Basically, as of v.6, the  default
> > behavior of Show is to get the PlotRange from the first plot listed.
> > See
> > what happens if you reverse it.
>
> > Show[bot, top]
>
> > The way to get something more like you are expecting is to set
> > PlotRange->Automatic within Show.
>
> > bot = Plot3D[-Sqrt[1 - (x^2 + y^2)], {x, -1, 1}, {y, -1, 1}];
> > top = Plot3D[+Sqrt[1 - (x^2 + y^2)], {x, -1, 1}, {y, -1, 1}];
> > Show[top, bot, PlotRange -> Automatic]
>
> > You might also want to set the BoxRatios.
>
> > bot = Plot3D[-Sqrt[1 - (x^2 + y^2)], {x, -1, 1}, {y, -1, 1}];
> > top = Plot3D[+Sqrt[1 - (x^2 + y^2)], {x, -1, 1}, {y, -1, 1}];
> > Show[top, bot, PlotRange -> Automatic, BoxRatios -> {1, 1, 1}]
>
> > I greatly dislike this new behavior of Show, for what it's worth. The
> > folks at WRI argue that because of all the new graphics options (e.g.,
> > Filling), it would not make sense to combine the PlotRange
> > automatically
> > (as Show did in previous versions of Mathematica). Personally, I
> > find it
> > to be a pain in the neck to have to ask for PlotRange->Automatic
> > virtually every time I use Show, and my students often forget and get
> > burned by it. I would much prefer PlotRange->Automatic to be the
> > default
> > in Show, and to set my own PlotRange manually on those infrequent
> > occasions when I need something else. And as for the argument that
> > setting a PlotRange automatically from the combined plots isn't always
> > appropriate, why not provide an easy way to tell Show to use the
> > PlotRange from a particular plot? Something like PlotRange->{1} to get
> > the PlotRange from the first plot, PlotRange->{2} to get the range
> > from
> > the 2nd plot, etc., would do the job when needed, and still allow
> > PlotRange->Automatic (which for me is almost always what I want) to be
> > the default.
>
> > I just now discovered, BTW, that
>
> > SetOptions[Show, PlotRange -> Automatic]
>
> > does not even work. It generates an error message claiming that
> > "PlotRange is not a known option for Show".
>
> > --
> > Helen Read
> > University of Vermont

• References:
  • Re: No Show
    • From: Helen Read <hpr@together.net>