Support Octave by new .m files

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Re: Support Octave by new .m files

Richard Crozier


On 09/07/2019 01:46, Hamed Shakouri wrote:

>
>
> On Mon, Jul 8, 2019 at 8:54 AM CROZIER Richard <[hidden email]
> <mailto:[hidden email]>> wrote:
>
>
>      >
>      >  >> It's easy to find. If you look to the functions/scripts you
>     see that
>      > these undocumented functions such as abcdchk are used.
>      > These are usually simple functions that there is no need for
>     research or
>      > hard work to develop. e,g, abcdchk just checks for the proper
>     sizes of
>      > the state space matrixes.
>      >
>
>     His point is that, you have just shown, and put on record in a public
>     mailing list that you have opened and examined the Matlab source code
>     for the control package functions. This means that The Mathworks (who
>     are the owners of the Matlab code) could claim that you have infringed
>     their copyright if you create code which is similar to theirs. Octave
>     code must be produced without any knowledge of how the code is
>     implemented in Matlab, see
>
>     https://en.wikipedia.org/wiki/Clean_room_design
>
>     for more information. Generally one should only look at the
>     documentation for Matlab code when developing an equivalent of a Matlab
>     function for Octave.
>
>     Otherwise, The Mathworks might sue the pants off the Octave project.
>
>     Hopefully this explains the concerns better?
>
>     Regards,
>
>     Richard
>     The University of Edinburgh is a charitable body, registered in
>     Scotland, with registration number SC005336.
>
>
> Hi Richard,
>
> I know that some codes are valuable properties of their builders.
> However, the function I mentioned is a very simple straightforward one
> that anybody can implement without knowing anything from its inside, its
> logic is clear.
> For the other, FOH discretization method, I didn't use a MatLab function
> (it's not easy to find how it works!). One can get the formulation from
> published papers.
>
> A reference is here:
> Bingulac, S. and Sinha, N. K.: 'On the identification of continuous-time
> multivariable systems from samples of input-output data', Proc. 7th
> International Conference on Mathematical and Computer Modelling,
> Chicago, 1989.
> Or:
> Franklin G., J. Powell, and M. Workman, Digital Control of Dynamic
> Systems, 1990.
> Thank you for the clarification.
>
> With Regards,
>
> Hamed Shakouri G.


The triviality of the code may or may not be important. What's important
is that you have apparently opened up the Matlab functions, had a good
rummage around, and now plan to implement Octave code which does the
same thing. A lawyer can make a case from this, and if the Octave
project doesn't have a lot of money to defend itself (it doesn't) they
could walk all over it in court. Unfortunately the Octave devs have to
be very very careful about this kind of thing.

Just to be clear, I'm not a core dev, just someone on the mailing list,
so don't take my opinion as the final word.

Regards,

Richard





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Re: Support Octave by new .m files

Hamed Shakouri

On Tue, Jul 9, 2019 at 3:13 AM CROZIER Richard <[hidden email]> wrote:


On 09/07/2019 01:46, Hamed Shakouri wrote:
>
>
> On Mon, Jul 8, 2019 at 8:54 AM CROZIER Richard <[hidden email]
> <mailto:[hidden email]>> wrote:
>
>
>      >
>      >  >> It's easy to find. If you look to the functions/scripts you
>     see that
>      > these undocumented functions such as abcdchk are used.
>      > These are usually simple functions that there is no need for
>     research or
>      > hard work to develop. e,g, abcdchk just checks for the proper
>     sizes of
>      > the state space matrixes.
>      >
>
>     His point is that, you have just shown, and put on record in a public
>     mailing list that you have opened and examined the Matlab source code
>     for the control package functions. This means that The Mathworks (who
>     are the owners of the Matlab code) could claim that you have infringed
>     their copyright if you create code which is similar to theirs. Octave
>     code must be produced without any knowledge of how the code is
>     implemented in Matlab, see
>
>     https://en.wikipedia.org/wiki/Clean_room_design
>
>     for more information. Generally one should only look at the
>     documentation for Matlab code when developing an equivalent of a Matlab
>     function for Octave.
>
>     Otherwise, The Mathworks might sue the pants off the Octave project.
>
>     Hopefully this explains the concerns better?
>
>     Regards,
>
>     Richard
>     The University of Edinburgh is a charitable body, registered in
>     Scotland, with registration number SC005336.
>
>
> Hi Richard,
>
> I know that some codes are valuable properties of their builders.
> However, the function I mentioned is a very simple straightforward one
> that anybody can implement without knowing anything from its inside, its
> logic is clear.
> For the other, FOH discretization method, I didn't use a MatLab function
> (it's not easy to find how it works!). One can get the formulation from
> published papers.
>
> A reference is here:
> Bingulac, S. and Sinha, N. K.: 'On the identification of continuous-time
> multivariable systems from samples of input-output data', Proc. 7th
> International Conference on Mathematical and Computer Modelling,
> Chicago, 1989.
> Or:
> Franklin G., J. Powell, and M. Workman, Digital Control of Dynamic
> Systems, 1990.
> Thank you for the clarification.
>
> With Regards,
>
> Hamed Shakouri G.


The triviality of the code may or may not be important. What's important
is that you have apparently opened up the Matlab functions, had a good
rummage around, and now plan to implement Octave code which does the
same thing. A lawyer can make a case from this, and if the Octave
project doesn't have a lot of money to defend itself (it doesn't) they
could walk all over it in court. Unfortunately the Octave devs have to
be very very careful about this kind of thing.

Just to be clear, I'm not a core dev, just someone on the mailing list,
so don't take my opinion as the final word.

Regards,

Richard







OK, thanks anyway. It is up to Octave team to manage such things. It was merely a suggestion.

With Regards,

Hamed Shakouri G.
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