Re: Clever Tricky Solutions
- To: mathgroup at smc.vnet.net
- Subject: [mg94187] Re: Clever Tricky Solutions
- From: Helen Read <hpr at together.net>
- Date: Sat, 6 Dec 2008 19:56:52 -0500 (EST)
- References: <27271771.1228394784179.JavaMail.root@m02> <ghavpg$o9j$1@smc.vnet.net> <ghdmvt$frc$1@smc.vnet.net>
- Reply-to: HPR <read at math.uvm.edu>
congruentialuminaire at yahoo.com wrote:
>
> I was thinking that maybe this is just a bug which Mathematica V6 introduced
> and which the PlotRange -> All specification "fixes". Indeed when I
> ran this on a V5.2 system, both graphs show as coded by Donald. I wish
> a WRI team member [coder or tester] would look into this and get back
> to all of us about:
>
> - is this a bug? Is it "fixed" in V7?
> - did the PlotRange default value [when unspecified] become different
> in V6, necessitating the need for this "fix" provided by David and
> Bobby?
This was discussed here at length when v6 came out last year. WRI
changed the default behavior of Show beginning with 6.0, because,
according to them, with the various new graphics options (Filling, etc.)
introduced in v6, it "often" does not make sense to combine the
PlotRanges of the individual graphics. So instead, Show now uses the
PlotRange from the first graphic by default. The v7 documentation for
Show discusses this under "Possible Issues" with an example illustrating
that "Show uses options from the first graphic". It suggests using
PlotRange->All to see the entire plot. However, PlotRange->All often
gives terrible results, so I tell my students to always set
PlotRange->Automatic in Show, which makes it behave the way it did
pre-v6. They often forget to do this, though, and don't understand why
their plots are cut off.
I greatly dislike this behavior, as I virtually *never* want the
PlotRange from the first plot. Rather, I want the PlotRanges combined
automatically by default, as Show did prior to v6. On the rare occasion
where I need something else, I can always specify the PlotRange
explicitly. I think it would make a lot more sense to have
PlotRange->Automatic the default in Show, with some way to set it to use
the PlotRange from the 1st graphic or the 2nd etc. if you need to.
Something like PlotRange->{1} to get the PlotRange from the first
graphic, or whatever.
SetOptions[Show, PlotRange -> Automatic] does not even work, BTW. You
get an error that "PlotRange is not an option for Show". So my students
and I are stuck having to type in PlotRange->Automatic about 99% of the
time when we use Show. If Automatic was still the default, we would
rarely have to specify a PlotRange in Show.
--
Helen Read
University of Vermont