Re: Axis layout of xyz in 3D plotting

Please, keep the mailing list in CC.

Octave's plotting system uses a right-handed coordinate system.

If you'd like to switch to a left handed coordinate system, reverse one of the axes.

Can you give an example where Octave uses a left-handed coordinate system when plotting for you?

Markus

Gesendet: Montag, 23. August 2021 um 13:27 Uhr

Von: "Tee Nor" <[email protected]>

An: "Markus Mützel" <[email protected]>

Betreff: Re: Axis layout of xyz in 3D plotting

Hello Markus,

Thank you very much for the help. I installed Octave 6.3.0 on Vista,

Apparently, On Debian 10.9.0 I'll have to re-build Octave 6.3.0 as

Debian 10 Octave version is 4.4.1. This issue has not changed between

versions.

Please examine the included attachment:

MathWorks (MathLab) and Octave are using the "Left-hand" coordinate system,

so it is not currently possible to change to the "Right handed" system.

In either case, the plots are correct as seen per the xyz numbers.

As indicated by the preferred statement, while developing textbooks etc,

the solution was to just leave out the axis information, avoiding confusion.

In my last note, the location (1,1,1) of ijk in both (a) and (b) are the same,

just flip (b) over, except x and y are swapped. Also, gui_mode() is now

considered an error in MS world. I do not plan to use MS.

Suggest adding a setup switch between right and left hand option.

Regards, T

On Sat, Aug 21, 2021 at 4:09 PM Markus Mützel <[email protected] > wrote:

Am 21. August 2021 um 08:52 Uhr schrieb "Tee Nor":

> Has anyone noticed,

> Most math and physics textbooks have the positive axis arrowheads direction layout as follows:

> x axis arrow pointing down and to the left,

> y axis arrow pointing to the right,

> z axis arrow pointing to the top.

> Using GNU Octave version 3.6.2,

> Please show how to make my positive axis look this way.

> My view always looks like x and y are swapped.

> Regards, T

Octave 3.6.2 is ancient and I don't have access to it to test in that version.

In version 6.3.0, the following command seems to rotate the axes in the way you describe:

view ([100, 30]);

HTH,

Markus