There's a "Plot Package" lab. In jqt, J803, labs are buried under the
Studio menu option of the Help menu. (in JHS, the studio option is a
top level menu item, but "Plot Package" becomes "Graphics: Plot
Package" and also I have to shut down nvidia's "experience" package to
get jhs to work in its default configuration. Mind you, I hardly ever
use that nvidia subsystem, but it tends to get re-enabled rather
easily, for some reason. I mention this because there's a significant
chance that new J users will also have that nvidia package installed,
and I do not think it's reasonable to assume that only active posters
will be reading this forum. Note also that the lab explicitly mentions
"Help|Studio|Advance" but in JHS, the Studio option does not occur
under "Help" and there is no "Help".)
I'll also note that steps is defined when I run that lab, and its definition is:
steps=: {. + (1&{ - {.) * (i.@>: % ])@{:
There is also some documentation for J's plot package in Henry's J for C:
http://www.jsoftware.com/help/jforc/graphics.htm
Also, the wiki has http://www.jsoftware.com/jwiki/Studio/Plot
but it looks like the initial page it links to --
http://www.jsoftware.com/jwiki/Plot -- would fail to load for me, more
often than not. That's the reference documentation, though, so if you
can get it to load, it can be handy.
Thanks,
--
Raul
On Sat, Mar 7, 2015 at 12:12 PM, Skip Cave <[email protected]> wrote:
> Raul,
>
> That was it! My algebraic skills have gotten rusty over the years. I'm
> going to have to work on polishing up my algebra, so I won't make these
> dumb mistakes. So here's the final result:
>
> http://bit.ly/1Be186L
>
> Now I want to plot this in J. I'll see if I can figure out how to work the
> plot verbs. Where is the documentation on the 3D plotting verb?
>
> Skip
>
>
> Skip Cave
> Cave Consulting LLC
>
> On Sat, Mar 7, 2015 at 6:30 AM, Raul Miller <[email protected]> wrote:
>
>> z = (c*(1 - ((x^2)%(a^2)) + ((y^2)%(b^2))))
>>
>> is different from
>>
>> c * ((1 - ((x^2)%(a^2)) + ((y^2)%(b^2))))^0.5
>>
>> When solving for z you need to take the square root of something.
>>
>> The equation you're working with looks like it got part of it chopped off.
>>
>> Perhaps it would be clearer if we reorganized things a bit:
>>
>> z =: c*(1 - rest) ^ 0.5
>>
>> where
>> rest=: ((x%a)^2) + (y%b)^2
>>
>> There's other ways of doing this, but basically you're working with a
>> root-mean-square type of equation.
>>
>> Thanks,
>>
>> --
>> Raul
>>
>> On Sat, Mar 7, 2015 at 3:32 AM, Skip Cave <[email protected]> wrote:
>> > Well, I tried plotting the equation
>> > z = (c*(1 - ((x^2)%(a^2)) + ((y^2)%(b^2))))
>> >
>> > And I don't get anything like a ellipsoid. Here's what I get...
>> > http://bit.ly/17Zou4t
>> > What is going wrong?
>> >
>> > Skip Cave
>> > Cave Consulting LLC
>> >
>> > On Sat, Mar 7, 2015 at 12:04 AM, Skip Cave <[email protected]>
>> wrote:
>> >
>> >> Yes, I just solved the Cartesian equation, and got the same answer. I
>> just
>> >> need the positive values of z, so I can take the absolute value of the
>> >> equation for the plot.
>> >>
>> >> Now I need to see if I can plot the ellipse by simply running x from
>> 1-10,
>> >> and then stepping y after each x pass. I want to see the zero values of
>> x
>> >> as well, making a plane that the half ellipse sets on.
>> >>
>> >> Skip
>> >>
>> >> On Mar 6, 2015 11:20 PM, "Raul Miller" <[email protected]> wrote:
>> >> >
>> >> > Of course you realize that there are either two or zero values of z
>> >> > for every value of x and y.
>> >> >
>> >> > That said,
>> >> > (((x^2)%(a^2)) + ((y^2)%(b^2)) + ((z^2)%(c^2))) = 1
>> >> > (((c^2)*((x^2)%(a^2)) + ((y^2)%(b^2)))+ ((z^2)) = c^2
>> >> > (z^2) = (c^2)*(1 - ((x^2)%(a^2)) + ((y^2)%(b^2)))
>> >> >
>> >> > a=:3
>> >> > b=:4
>> >> > c=:5
>> >> >
>> >> > z=:13 :'c * ((1 - ((x^2)%(a^2)) + ((y^2)%(b^2))))^0.5'
>> >> > z
>> >> > 5 * 0.5 ^~ 1 - (9 %~ 2 ^~ [) + 16 %~ 2 ^~ ]
>> >> >
>> >> > Or:
>> >> > z=:1 _1 */ c * 0.5 ^~ 1 - ((a^2) %~ 2 ^~ [) + (b^2) %~ 2 ^~ ]
>> >> >
>> >> > Does that help?
>> >> >
>> >> > Thanks,
>> >> >
>> >> > --
>> >> > Raul
>> >> >
>> >> > On Sat, Mar 7, 2015 at 12:10 AM, Skip Cave <[email protected]>
>> >> wrote:
>> >> > > Raul,
>> >> > >
>> >> > > Yes. What I need is a function f (x,y) using the Cartesian
>> coordinates
>> >> x &
>> >> > > y that will produce the z dimension in the ellipse when I step x & y
>> >> over
>> >> > > the plane.
>> >> > >
>> >> > > Skip
>> >> > >
>> >> > > Skip Cave
>> >> > > Cave Consulting LLC
>> >> > >
>> >> > > On Fri, Mar 6, 2015 at 11:03 PM, Raul Miller <[email protected]
>> >
>> >> wrote:
>> >> > >
>> >> > >> I imagine they'd go something like this:
>> >> > >>
>> >> > >> X=. a*((sin P) */ cos T)
>> >> > >> Y=. b*(((sin P) */ sin T)
>> >> > >> Z=. c*((cos P) +/ T*0)%2
>> >> > >>
>> >> > >> The assumption would be that when they are omitted they are 1.
>> >> > >>
>> >> > >> The trick is recognizing how these parametric equations correspond
>> to
>> >> > >> your original expression.
>> >> > >>
>> >> > >> Thanks,
>> >> > >>
>> >> > >> --
>> >> > >> Raul
>> >> > >>
>> >> > >> On Sat, Mar 7, 2015 at 12:00 AM, Skip Cave <
>> [email protected]>
>> >> > >> wrote:
>> >> > >> > Ok now I'm confused. Nowhere do I see where we set the length of
>> the
>> >> > >> three
>> >> > >> > axes a, b, and c. Also the step verb has lots of variables in it,
>> >> like a,
>> >> > >> > w, n, and z that I don't see defined anywhere.
>> >> > >> > steps=: 3 : 'a+(w)*(i.n+1)%n[w=.z-a[''a z n''=.y'
>> >> > >> >
>> >> > >> > How do I change the lengths of the axes a, b,and c?
>> >> > >> >
>> >> > >> > Skip Cave
>> >> > >> > Cave Consulting LLC
>> >> > >> >
>> >> > >> > On Fri, Mar 6, 2015 at 10:25 PM, Joe Bogner <[email protected]
>> >
>> >> wrote:
>> >> > >> >
>> >> > >> >> I don't know what I'm doing other than copy/pasting, but the
>> >> example
>> >> > >> from
>> >> > >> >> the plot demo looks pretty close:
>> >> > >> >>
>> >> > >> >> load 'plot'
>> >> > >> >> pd 'clear'
>> >> > >> >> steps=: 3 : 'a+(w)*(i.n+1)%n[w=.z-a[''a z n''=.y'
>> >> > >> >> P=. steps 0 1p1 30
>> >> > >> >> T=. steps 0 2p1 40
>> >> > >> >> X=. ((sin P) */ cos T)
>> >> > >> >> Y=. ((sin P) */ sin T)
>> >> > >> >> Z=. ((cos P) +/ T*0)%2
>> >> > >> >>
>> >> > >> >> pd 'backcolor blue'
>> >> > >> >> pd 'new 0 0 1000 1000'
>> >> > >> >>
>> >> > >> >> pd 'type surface'
>> >> > >> >> pd 'viewpoint 2 2 2;color grayscale'
>> >> > >> >> pd X;Y;Z
>> >> > >> >> pd 'show'
>> >> > >> >>
>> >> > >> >>
>> >> > >> >>
>> >> > >> >> On Fri, Mar 6, 2015 at 11:18 PM, Raul Miller <
>> >> [email protected]>
>> >> > >> >> wrote:
>> >> > >> >>
>> >> > >> >> > This is something of an aside - I don't know what I'm doing
>> yet,
>> >> well
>> >> > >> >> > enough to implement this via jhs, but here's an ellipsoid:
>> >> > >> >> >
>> >> > >> >> > https://www.shadertoy.com/view/XtlGDX
>> >> > >> >> >
>> >> > >> >> > You can tweak the a, b, and c radius values near the top of
>> the
>> >> script
>> >> > >> >> > (which should display on the right side of the screen) and hit
>> >> the
>> >> > >> >> > play button to see the change.
>> >> > >> >> >
>> >> > >> >> > Thanks,
>> >> > >> >> >
>> >> > >> >> > --
>> >> > >> >> > Raul
>> >> > >> >> >
>> >> > >> >> > On Fri, Mar 6, 2015 at 10:38 PM, Skip Cave <
>> >> [email protected]>
>> >> > >> >> > wrote:
>> >> > >> >> > > Looking a bit better, but no cigar:
>> >> > >> >> > >
>> >> > >> >> > > a=:3[b=:3[c=:3
>> >> > >> >> > >
>> >> > >> >> > > X=:4 :0
>> >> > >> >> > >
>> >> > >> >> > > a*(cos x)*cos y
>> >> > >> >> > >
>> >> > >> >> > > )
>> >> > >> >> > >
>> >> > >> >> > > Y=:4 :0
>> >> > >> >> > >
>> >> > >> >> > > b*(cos x)*sin y
>> >> > >> >> > >
>> >> > >> >> > > )
>> >> > >> >> > >
>> >> > >> >> > > Z=:3 :0
>> >> > >> >> > >
>> >> > >> >> > > c*(sin y)
>> >> > >> >> > >
>> >> > >> >> > > )
>> >> > >> >> > >
>> >> > >> >> > > steps=: 3 : 'a+(w)*(i.n+1)%n[w=.z-a[''a z n''=.y'
>> >> > >> >> > >
>> >> > >> >> > > draw=:3 :0
>> >> > >> >> > >
>> >> > >> >> > > angles=: steps _1p1 1p1 100
>> >> > >> >> > >
>> >> > >> >> > > uangles =: steps _1.5708 1.5708 100
>> >> > >> >> > >
>> >> > >> >> > > x=. uangles X"0 _ angles
>> >> > >> >> > >
>> >> > >> >> > > y=. uangles Y"0 _ angles
>> >> > >> >> > >
>> >> > >> >> > > z=. Z uangles
>> >> > >> >> > >
>> >> > >> >> > > 'surface' plot x;y;z
>> >> > >> >> > >
>> >> > >> >> > > )
>> >> > >> >> > >
>> >> > >> >> > > draw''
>> >> > >> >> > >
>> >> > >> >> > >
>> >> > >> >> > > output at: http://bit.ly/1wNlQe3
>> >> > >> >> > >
>> >> > >> >> > >
>> >> > >> >> > > Skip Cave
>> >> > >> >> > > Cave Consulting LLC
>> >> > >> >> > >
>> >> > >> >> > > On Fri, Mar 6, 2015 at 9:18 PM, Raul Miller <
>> >> [email protected]>
>> >> > >> >> > wrote:
>> >> > >> >> > >
>> >> > >> >> > >> steps=: 3 : 'a+(w)*(i.n+1)%n[w=.z-a[''a z n''=.y'
>> >> > >> >> > >>
>> >> > >> >> > >> Thanks,
>> >> > >> >> > >>
>> >> > >> >> > >> --
>> >> > >> >> > >> Raul
>> >> > >> >> > >>
>> >> > >> >> > >> On Fri, Mar 6, 2015 at 10:08 PM, Skip Cave <
>> >> > >> [email protected]>
>> >> > >> >> > >> wrote:
>> >> > >> >> > >> > Here's what I got whaen I ran Jon's code:
>> >> > >> >> > >> >
>> >> > >> >> > >> > a=:3[b=:3[c=:3
>> >> > >> >> > >> >
>> >> > >> >> > >> > X=:4 :0
>> >> > >> >> > >> >
>> >> > >> >> > >> > a*(cos x)*cos y
>> >> > >> >> > >> >
>> >> > >> >> > >> > )
>> >> > >> >> > >> >
>> >> > >> >> > >> > Y=:4 :0
>> >> > >> >> > >> >
>> >> > >> >> > >> > b*(cos x)*sin y
>> >> > >> >> > >> >
>> >> > >> >> > >> > )
>> >> > >> >> > >> >
>> >> > >> >> > >> > Z=:3 :0
>> >> > >> >> > >> >
>> >> > >> >> > >> > c*(sin y)
>> >> > >> >> > >> >
>> >> > >> >> > >> > )
>> >> > >> >> > >> >
>> >> > >> >> > >> > draw=:3 :0
>> >> > >> >> > >> >
>> >> > >> >> > >> > angles=: steps _1p1 1p1 100
>> >> > >> >> > >> >
>> >> > >> >> > >> > uangles =: steps _1.5708 1.5708 100
>> >> > >> >> > >> >
>> >> > >> >> > >> > x=. uangles X"0 _ angles
>> >> > >> >> > >> >
>> >> > >> >> > >> > y=. uangles Y"0 _ angles
>> >> > >> >> > >> >
>> >> > >> >> > >> > z=. Z uangles
>> >> > >> >> > >> >
>> >> > >> >> > >> > 'surface' plot x;y;z
>> >> > >> >> > >> >
>> >> > >> >> > >> > )
>> >> > >> >> > >> >
>> >> > >> >> > >> > draw''
>> >> > >> >> > >> >
>> >> > >> >> > >> > |value error: steps
>> >> > >> >> > >> >
>> >> > >> >> > >> > | angles=: steps _3.14159 3.14159 100
>> >> > >> >> > >> >
>> >> > >> >> > >> >
>> >> > >> >> > >> > Skip Cave
>> >> > >> >> > >> > Cave Consulting LLC
>> >> > >> >> > >> >
>> >> > >> >> > >> > On Fri, Mar 6, 2015 at 8:56 PM, Jon Hough <
>> >> [email protected]>
>> >> > >> >> > wrote:
>> >> > >> >> > >> >
>> >> > >> >> > >> >>
>> >> > >> >> > >> >> I butchered Raul's script slightly. But the resulting
>> >> graph is
>> >> > >> >> still
>> >> > >> >> > >> >> weird. Not sure if it's an improvement.
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >> a=:3[b=:3[c=:3
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >> X=:4 :0
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >> a*(cos x)*cos y
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >> )
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >> Y=:4 :0
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >> b*(cos x)*sin y
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >> )
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >> Z=:3 :0
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >> c*(sin y)
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >> )
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >> draw=:3 :0
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >> angles=: steps _1p1 1p1 100
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >> uangles =: steps _1.5708 1.5708 100
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >> x=. uangles X"0 _ angles
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >> y=. uangles Y"0 _ angles
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >> z=. Z uangles
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >> 'surface' plot x;y;z
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >> )
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> > >> >> draw''
>> >> > >> >> > >> >>
>> >> > >> >> > >> >> > From: [email protected]
>> >> > >> >> > >> >> > To: [email protected]
>> >> > >> >> > >> >> > Date: Sat, 7 Mar 2015 02:46:35 +0000
>> >> > >> >> > >> >> > Subject: Re: [Jprogramming] Plotting a 3D Ellipse
>> >> > >> >> > >> >> >
>> >> > >> >> > >> >> > It seems you are using [-pi,pi] as the range of all
>> your
>> >> > >> angles.I
>> >> > >> >> > >> think
>> >> > >> >> > >> >> you need to use [-pi/2,pi/2] as the range for the u
>> >> argument (in
>> >> > >> >> the
>> >> > >> >> > >> >> wikipedia page).
>> >> > >> >> > >> >> >
>> >> > >> >> > >> >> > > From: [email protected]
>> >> > >> >> > >> >> > > Date: Fri, 6 Mar 2015 21:35:37 -0500
>> >> > >> >> > >> >> > > To: [email protected]
>> >> > >> >> > >> >> > > Subject: Re: [Jprogramming] Plotting a 3D Ellipse
>> >> > >> >> > >> >> > >
>> >> > >> >> > >> >> > > Hmm...
>> >> > >> >> > >> >> > >
>> >> > >> >> > >> >> > > I notice that load'graph' no longer provides the
>> steps
>> >> verb
>> >> > >> >> > >> mentioned
>> >> > >> >> > >> >> > > in http://www.jsoftware.com/books/pdf/expmath.pdf
>> >> > >> >> > >> >> > >
>> >> > >> >> > >> >> > > So here's a workalike:
>> >> > >> >> > >> >> > > steps=: 3 : 'a+(w)*(i.n+1)%n[w=.z-a[''a z n''=.y'
>> >> > >> >> > >> >> > >
>> >> > >> >> > >> >> > > and that gives us an example of a surface plot.
>> >> > >> >> > >> >> > >
>> >> > >> >> > >> >> > > Next, we need a parametric representation of the
>> >> ellipse,
>> >> > >> and
>> >> > >> >> > >> >> > >
>> >> http://en.wikipedia.org/wiki/Ellipsoid#Parameterization
>> >> > >> looks
>> >> > >> >> > like
>> >> > >> >> > >> a
>> >> > >> >> > >> >> > > plausible approach there.
>> >> > >> >> > >> >> > >
>> >> > >> >> > >> >> > > Using that, and
>> >> > >> >> http://www.jsoftware.com/help/jforc/graphics.htm
>> >> > >> >> > >> as a
>> >> > >> >> > >> >> > > starting point, it seems to me that I ought to be
>> able
>> >> to
>> >> > >> draw
>> >> > >> >> an
>> >> > >> >> > >> >> > > ellipse like this:
>> >> > >> >> > >> >> > >
>> >> > >> >> > >> >> > > a=:3[b=:4[c=:5
>> >> > >> >> > >> >> > >
>> >> > >> >> > >> >> > > X=:4 :0~
>> >> > >> >> > >> >> > > a*(cos x)*/cos y
>> >> > >> >> > >> >> > > )
>> >> > >> >> > >> >> > >
>> >> > >> >> > >> >> > > Y=:4 :0~
>> >> > >> >> > >> >> > > b*(cos x)*/sin y
>> >> > >> >> > >> >> > > )
>> >> > >> >> > >> >> > >
>> >> > >> >> > >> >> > > Z=:4 :0~
>> >> > >> >> > >> >> > > c*(sin x)*/1: y
>> >> > >> >> > >> >> > > )
>> >> > >> >> > >> >> > >
>> >> > >> >> > >> >> > > draw=:3 :0
>> >> > >> >> > >> >> > > angles=: steps _1p1 1p1 100
>> >> > >> >> > >> >> > > x=. X angles
>> >> > >> >> > >> >> > > y=. Y angles
>> >> > >> >> > >> >> > > z=. Z angles
>> >> > >> >> > >> >> > > 'surface' plot x;y;z
>> >> > >> >> > >> >> > > )
>> >> > >> >> > >> >> > >
>> >> > >> >> > >> >> > > draw''
>> >> > >> >> > >> >> > >
>> >> > >> >> > >> >> > > Sadly, that's not an ellipse.
>> >> > >> >> > >> >> > >
>> >> > >> >> > >> >> > > But I do not have enough familiarity with plot to
>> know
>> >> > >> whether
>> >> > >> >> > I've
>> >> > >> >> > >> >> > > screwed up my math or if there's a defect in plot
>> -- I
>> >> don't
>> >> > >> >> know
>> >> > >> >> > >> how
>> >> > >> >> > >> >> > > to isolate the problem.
>> >> > >> >> > >> >> > >
>> >> > >> >> > >> >> > > That said, a quick test with a 3d model of a cube:
>> >> > >> >> > >> >> > >
>> >> > >> >> > >> >> > > 'surface' plot ;/|:#:i.8
>> >> > >> >> > >> >> > > |NaN error: ncile
>> >> > >> >> > >> >> > >
>> >> > >> >> > >> >> > > ...suggests that plot isn't really designed to
>> >> represent 3d
>> >> > >> >> > solids.
>> >> > >> >> > >> >> > >
>> >> > >> >> > >> >> > > Still, that does not eliminate any potential errors
>> on
>> >> my
>> >> > >> part.
>> >> > >> >> > >> >> > >
>> >> > >> >> > >> >> > > On the other hand, maybe the right approach would be
>> >> to use
>> >> > >> jhs
>> >> > >> >> > and
>> >> > >> >> > >> >> > > generate a distance field renderer along the lines
>> of
>> >> what
>> >> > >> you
>> >> > >> >> > see
>> >> > >> >> > >> at
>> >> > >> >> > >> >> > > shadertoy.com.
>> >> > >> >> > >> >> > >
>> >> > >> >> > >> >> > > I'll have to think a bit to see if I can pull off
>> >> something
>> >> > >> >> like
>> >> > >> >> > >> that.
>> >> > >> >> > >> >> > > (I think that that would only work for people who
>> have
>> >> > >> adequate
>> >> > >> >> > >> >> > > graphics hardware support. But I think you have a
>> >> suitable
>> >> > >> >> > graphics
>> >> > >> >> > >> >> > > card?)
>> >> > >> >> > >> >> > >
>> >> > >> >> > >> >> > > Thanks,
>> >> > >> >> > >> >> > >
>> >> > >> >> > >> >> > > --
>> >> > >> >> > >> >> > > Raul
>> >> > >> >> > >> >> > >
>> >> > >> >> > >> >> > >
>> >> > >> >> > >> >> > > On Fri, Mar 6, 2015 at 7:10 PM, Skip Cave <
>> >> > >> >> > [email protected]>
>> >> > >> >> > >> >> wrote:
>> >> > >> >> > >> >> > > > I want to plot a 3D ellipse (ellipsoid) and then
>> be
>> >> able
>> >> > >> to
>> >> > >> >> > change
>> >> > >> >> > >> >> the
>> >> > >> >> > >> >> > > > lengths of the three axes. The equation of an
>> >> ellipse with
>> >> > >> >> axis
>> >> > >> >> > >> >> lengths of
>> >> > >> >> > >> >> > > > a, b, & c is:
>> >> > >> >> > >> >> > > >
>> >> > >> >> > >> >> > > > ((x^2)%(a^2)) + ((y^2)%(b^2)) + ((z^2)%(c^2)) = 1
>> >> > >> >> > >> >> > > >
>> >> > >> >> > >> >> > > > How can I arrange this so it can be plotted in a
>> 3-D
>> >> plot
>> >> > >> in
>> >> > >> >> J,
>> >> > >> >> > >> and
>> >> > >> >> > >> >> then be
>> >> > >> >> > >> >> > > > able to experiment with the lengths of the axes?
>> >> > >> >> > >> >> > > >
>> >> > >> >> > >> >> > > > Skip
>> >> > >> >> > >> >> > > >
>> >> > >> >> > >> >> > > > Skip Cave
>> >> > >> >> > >> >> > > > Cave Consulting LLC
>> >> > >> >> > >> >> > > >
>> >> > >> >> > >> >>
>> >> > >> >> >
>> >> ----------------------------------------------------------------------
>> >> > >> >> > >> >> > > > For information about J forums see
>> >> > >> >> > >> >> http://www.jsoftware.com/forums.htm
>> >> > >> >> > >> >> > >
>> >> > >> >> > >>
>> >> > >>
>> ----------------------------------------------------------------------
>> >> > >> >> > >> >> > > For information about J forums see
>> >> > >> >> > >> http://www.jsoftware.com/forums.htm
>> >> > >> >> > >> >> >
>> >> > >> >> > >> >> >
>> >> > >> >> >
>> >> ----------------------------------------------------------------------
>> >> > >> >> > >> >> > For information about J forums see
>> >> > >> >> > >> http://www.jsoftware.com/forums.htm
>> >> > >> >> > >> >>
>> >> > >> >> > >> >>
>> >> > >> >> >
>> >> ----------------------------------------------------------------------
>> >> > >> >> > >> >> For information about J forums see
>> >> > >> >> > http://www.jsoftware.com/forums.htm
>> >> > >> >> > >> >>
>> >> > >> >> > >> >
>> >> > >> >>
>> >> ----------------------------------------------------------------------
>> >> > >> >> > >> > For information about J forums see
>> >> > >> >> > http://www.jsoftware.com/forums.htm
>> >> > >> >> > >>
>> >> > >>
>> ----------------------------------------------------------------------
>> >> > >> >> > >> For information about J forums see
>> >> > >> >> http://www.jsoftware.com/forums.htm
>> >> > >> >> > >>
>> >> > >> >> > >
>> >> > >>
>> ----------------------------------------------------------------------
>> >> > >> >> > > For information about J forums see
>> >> > >> http://www.jsoftware.com/forums.htm
>> >> > >> >> >
>> >> ----------------------------------------------------------------------
>> >> > >> >> > For information about J forums see
>> >> > >> http://www.jsoftware.com/forums.htm
>> >> > >> >> >
>> >> > >> >>
>> >> ----------------------------------------------------------------------
>> >> > >> >> For information about J forums see
>> >> http://www.jsoftware.com/forums.htm
>> >> > >> >>
>> >> > >> >
>> >> ----------------------------------------------------------------------
>> >> > >> > For information about J forums see
>> >> http://www.jsoftware.com/forums.htm
>> >> > >>
>> ----------------------------------------------------------------------
>> >> > >> For information about J forums see
>> >> http://www.jsoftware.com/forums.htm
>> >> > >>
>> >> > >
>> ----------------------------------------------------------------------
>> >> > > For information about J forums see
>> http://www.jsoftware.com/forums.htm
>> >> > ----------------------------------------------------------------------
>> >> > For information about J forums see
>> http://www.jsoftware.com/forums.htm
>> >>
>> > ----------------------------------------------------------------------
>> > For information about J forums see http://www.jsoftware.com/forums.htm
>> ----------------------------------------------------------------------
>> For information about J forums see http://www.jsoftware.com/forums.htm
>>
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
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For information about J forums see http://www.jsoftware.com/forums.htm
