Re: Yet another Mathematica docs whopper
- To: mathgroup at smc.vnet.net
- Subject: [mg47112] Re: Yet another Mathematica docs whopper
- From: "Peltio" <peltio at twilight.zone>
- Date: Fri, 26 Mar 2004 03:55:57 -0500 (EST)
- References: <c3udt9$9pd$1@smc.vnet.net>
- Reply-to: "Peltio" <peltioNOSP at Mdespammed.com.invalid>
- Sender: owner-wri-mathgroup at wolfram.com
"J Krugman" wrote
> ??AspectRatio
> AspectRatio is an option for Show and [snip]
> ^^^^^^^^^^^^^^^^^^^^^
> SetOptions[Show, AspectRatio->Automatic];
> SetOptions::optnf: AspectRatio is not a known option for Show.
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>I am furious, because I spend an unreasonable amount of time
>resolving inadequacies like this one in the Mathematica documentation.
This might at first look like a glitch of the kernel, since AspectRatio is
accepted as an option by Show. Try
Show[Graphics[Point[{0,0}],Frame->True,AspectRatio->0.5]
Show[Graphics3D[Point[{0,0,0}], AspectRatio->0.5]
to see that this is the case. My wild guess is that SetOptions won't let you
set a default value for AspectRatio because there may be cases where that
option wouldn't work. For example the option Frame can't be assigned to Show
when it is drawing 3D graphics. I can't name right now a graphics object
that does not accept AspectRatio, but I surmise there must be at least one.
True, this mechanism is a little subtle and should be better documented.
Perhaps the first message should be modified into something like:
"AspectRatio is an option for Show (when used with certain functions) and
related functions, which specifies the ratio of height to width for a plot."
It would be even Better to have separate error messages for incorrect
options: one for unknown options
SetOptions::optnf: Accuracy is not a known option for Show.
and one for 'possibly incompatible option'.
SetOptions::optng: AspectRatio is not a generally valid option for Show.
But I guess that this would mean to revise the whole option managing
business : )
cheers,
Peltio
--
Invalid address in reply-to. Crafty demunging required to mail me.