Re: A 3D Plot Query
- To: mathgroup at smc.vnet.net
- Subject: [mg94374] Re: A 3D Plot Query
- From: Murray Eisenberg <murray at math.umass.edu>
- Date: Thu, 11 Dec 2008 03:46:54 -0500 (EST)
- Organization: Mathematics & Statistics, Univ. of Mass./Amherst
- References: <31362096.1228736527369.JavaMail.root@m02> <200812091159.GAA20944@smc.vnet.net> <31958869.1228906532926.JavaMail.root@m02> <000001c95ae9$3810e180$a832a480$@net>
- Reply-to: murray at math.umass.edu
As always with "Presentations" results, lovely.
It's still galling to me that Mathematica doesn't make it MUCH easier to
reproduce the kind of 3D axes mathematicians routinely draw.
David Park wrote:
> Needs["Presentations`Master`"]
>
> With[
> {a = 1},
> Draw3DItems[
> {Opacity[.5, Brown],
> ParametricDraw3D[{r Cos[\[Theta]], r Sin[\[Theta]],
> 2 - r^2}, {\[Theta], 0, \[Pi]/2}, {r, 0, a},
> PlotPoints -> {30, 10},
> Mesh -> None,
> MaxRecursion -> 3],
> Opacity[1, Black],
> DrawArrow3DAxes[{0, 0, 1}, 1, .1],
> VerticalText3D["x", {1.2 a, 0, 2 - a^2}, 0, {.1, .1}],
> VerticalText3D["y", {0, 1.2 a, 2 - a^2}, 90 \[Degree], {.1, .1}],
> VerticalText3D["z", {0, 0, 2.1}, 90 \[Degree], {.1, .1}],
> VerticalText3D["a", {0, a/2, 2 - .9 a^2}, 90 \[Degree], {.1, .1}]},
> NeutralLighting[.0, .5, .1],
> NiceRotation,
> PlotRange -> {{-.2 a, 1.4 a}, {-.2 a, 1.4 a}, All},
> ViewPoint -> {5, 5, 3},
> BoxRatios -> Automatic,
> Boxed -> False,
> PlotLabel -> Style[z == 2 - Sqrt[x^2 + y^2], 16]]
> ]
>
>
> David Park
> djmpark at comcast.net
> http://home.comcast.net/~djmpark/
>
>
>
>
> From: Murray Eisenberg [mailto:murray at math.umass.edu]
>
>
> Another "for engineers and scientists" version of a graph -- and not
> what the poster requested. As I understand the query, what is desired
> is the positive semi-axes shown emanating from the origin, with z up, x
> forward, and y to the right (roughly). No frame.
>
> David Park wrote:
>> Sid,
>>
>> Not silly at all.
>>
>> Use cylindrical coordinates and ParametricPlot3D to get a surface with a
>> circular base.
>>
>> Use the ViewPoint option to get the x and y axes in the position you want.
>>
>> With[{a = 5},
>> ParametricPlot3D[{r Cos[\[Theta]], r Sin[\[Theta]],
>> 2 - r^2}, {\[Theta], 0, 2 \[Pi]}, {r, 0, a},
>> PlotPoints -> {30, 10},
>> MaxRecursion -> 3,
>> AxesLabel -> {"x", "y", "z"},
>> ViewPoint -> {5, 5, 3},
>> BoxRatios -> {1, 1, 1}]
>> ]
>>
>>
>> David Park
>> djmpark at comcast.net
>> http://home.comcast.net/~djmpark/
>>
>>
>> From: pcoords29 at gmail.com [mailto:pcoords29 at gmail.com]
>>
>>
>> Hi,
>>
>> This may sound silly, but I can't get it to work. (I'm using v 6.0)
>>
>> How do I get my 3D plots look as given in textbooks, ie. with the y-
>> axis pointing to the right, the z-axis up and x-axis pointing out of
>> the paper/screen ( showing the first octant)? I mean the kind of
>> plots one draws on paper when working out surface integrals in
>> Calculus classes.
>>
>> If this is of any help, I'd like to get the plot of the paraboloid
>>
>> z = 2-(x^2+y^2), as given in Fig. 10-10 of Spiegel's Advanced
>> Calculus, Schaum Series.
>>
>> I tried
>>
>> Plot3D[2 - (x^2 + y^2), {x, -a, a}, {y, -a, a}],
>>
>> with various values of a. Unfortunately, none of them look like the
>> traditional cap-shaped paraboloid.
>>
>> Thanks for any help.
>>
>> Sid.
>>
>>
>>
>>
>>
>>
>
--
Murray Eisenberg murray at math.umass.edu
Mathematics & Statistics Dept.
Lederle Graduate Research Tower phone 413 549-1020 (H)
University of Massachusetts 413 545-2859 (W)
710 North Pleasant Street fax 413 545-1801
Amherst, MA 01003-9305
- References:
- RE: A 3D Plot Query
- From: "David Park" <djmpark@comcast.net>
- RE: A 3D Plot Query