ecterrab

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20 years, 21 days

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These are replies submitted by ecterrab

@zenterix 
_i is, indeed, something special after you load the Physics:-Vectors package, e.g. via with(Physics:-Vectors). After that, _i is a unit vector in the x direction, with its mathematical properties all active (see the help page ?Physics:-Vectors)

Edgardo S. Cheb-Terrab
Physics, Differential Equations and Mathematical Functions, Maplesoft

In order to give you feedback it is necessary to reproduce the problem - not possible with your description. Could you please upload a worksheet showing the problem (include text pointing at the problem and what is what you were expecting please). For that purpose, use the Green arrow you see when you write a question or reply to it. Thanks

Edgardo S. Cheb-Terrab
Physics, Differential Equations and Mathematical Functions, Maplesoft.

@C_R 
Thanks for your comments. The equation returned is " expression = 0 ", which is mathematically the same as " - expression = 0 ". In particular, I tweaked the design so that if Lagrange's equation is of the form "- A - B = 0", then multiply by -1 to return "A + B = 0". I will give this tweak further thought.

Edgardo S. Cheb-Terrab
Physics, Differential Equations and MathematicalFunctions, Maplesoft

@Scot Gould 
Indeed. Count on that.

Meantime, regarding the problem in PackageTools mentioned in this post, I added a fix to PackageTools within the Maplesoft Physics Updates v.1357, so after installing that version of the Physics Updates using the MapleCloud toolbar (that works), you can install subsequent versions as usual by entering Physics:-Version(latest) directly in the GUI (worksheet or document).

Edgardo S. Cheb-Terrab
Physics, Differential Equations and Mathematical Functions, Maplesoft

@Rouben Rostamian  

The problem is still that you don't have the current version of the updated code - Maplesoft Physics Updates. Here are the details:


 

Edgardo S. Cheb-Terrab
Physics, Differential Equations and Mathematical Functions, Maplesoft

Hi @Rouben Rostamian  
I see your version of the Physics Updates is 1342. I have v.1355, and am unable to reproduce the problem. I get

So, could you please update to the current Updates; or otherwise execute tracelast after the error message appears (you may need to repeat the operation twice). That may turn ON the lights. Without reproducing the problem, it cannot be "fixed".

Edgardo S. Cheb-Terrab
Physics, Differential Equations and Mathematical Functions, Maplesoft

@nm 
Sigh ... you are right. Somehow, Maple 2022.2 has this problem. You can still install the Updates clicking the MapleCloud toolbar. I tried now, it works.

@nm 

Are you trying from TTY Maple? If so, that is the problem, reported already. You need to update from Maple's GUI, the worksheet, as in open a Maple worksheet and there input Physics:-Version(latest), or use the icons of the MapleCloud toolbar. Both methods work fine for everybody as far as I know.

@acer 
Very interesting cocktail of commands ... Have you tried with different orderings for the output of indets(expr,suffixed(P)? That, I think, is the important question, since the output of indets is a set and the ordering is not predictable with ease. 

Either way, behind the scenes, it is `simplify/size` doing key parts of the job (if you assign `simplify/size` := u -> u; the superb compactification you achieved in your last input line disappears entirely). But I wonder whether the core idea I see in thaw(simplify(collect(expr, [G1, P2, P5], freeze@simplify))) - if it is not so sensitive to the ordering returned by indets (I see you are choosing by hand [G1, P2, P5]) - could be somehow used to improve `simplify/size` itself. In the latest Maplesoft Physics Updates, there is a version of `simplify/size` that works better than the one in Maple 2022.2, but it doesn't achieve the compactification you achieved. The codegen[optimize])(..., tryhard) mentioned by @Carl Love is also an excellent suggestion. This command, `simplify/size`, is relatively good, but being key functionality, any improvement is very welcome!

Edgardo S. Cheb-Terrab
Physics, Differential Equations and Mathematical Functions, Maplesoft

@Ahmed111 
After removing that unnecessary transformation equation, dchange does not interrupt with an error message anymore; that answers your question. Fix also pde -> pde1 in your input and check all of it. Your transformation - the way you present it - involves var[1] and var[2]. There is however nothing like that in the equation you are transforming. Therefore, dchange "does noting" - because nothing is to be done. Your old variables are x and t, only. See the help page ?dchange for examples on how to use the command.

@Ronan 
No that I know of. It is not difficult to write one though - a matter of time only. I preferred to not invest on that - prefer everything in white and black, but did tweak Komodo in several ways for fast-programming activity.

Komodo has this useful functionality where you can program macros, assign triggering key combos, and have the output in a window at the bottom. I have one I call "mint selection" with the purpose you ask, that is to flash up bugs in a portion of code (possibly a whole file).

It is a good example of things I didn't find how to do in other editors so easily, so worth showing here as an example. I want to "Pass selection as input" (an option in Komodo's macros), where by selection I mean "something highlighted with the mouse", and on that selection, execute :
<Maple installation>/bin/mint -s -i 2 -I ~/Maple/lib -l

and in this Komodo macro I have "Command Output Tab", so that the output is presented on a window that opens at the bottom, and there I see, exactly where is the problem with a portion of code I wrote. I cannot write in that output window but I can copy something I see in it and paste in the working window. All extremely useful.

Komodo has several other facilities, I have/use approx 10 macros. It is a pity for me that its development for Macintosh stopped (I use Mac). I managed to have a working version for Monterrey and previous OS versions. Not for Ventura yet.

Edgardo S. Cheb-Terrab
Physics, Differential Equations and Mathematical Functions, Maplesoft

@zenterix 
I am forwarding the problem you posted to the people who take care of that, adding it to the database of issues too.

On the other topic you mentioned, I missed saying that - for programming purposes (not interactive mathematics) - I use a Programmer's File Editor. I do not program within a Maple input line. For me, that is just not comfortable, even if you work using 1D-Math notation. A programmer's editor has significant useful tools. I use a tweaked version of Komodo, but many good programmer editors exist. 

@nm 
Your question is answered in my previous answer; read it slower. I said "Regarding another part of your question, dsolve matches c__n to _Cn only for the integration constants that it introduces / uses, not for al possiblel n (infinitely many)." Pass a fourth order ODE that gets solved and you will see 4 c__n matched to _Cn, and not more than that.

@acer 
I see I wasn't as clear as I thought. In my reply, I mentioned dsolve((2)). Not dsolve((2), arbitraryconstants = subscripted). So, using dsolve((2)), not Physics, no arbitraryconstants = ..., no Maple/toolbox, no mapleinit file, nada, so in that state, not only Maple 2022.2 and 2022.1 trigger the same Warning message, which - I understand - is the issue of this thread, but also Maple 2021 triggers that undesired Warning. Try it; you can download "not related to physics.mw", the worksheet I used to produce my previous reply.

To summarize, this is not related to Physics. Somehow, there is something with the Units package and the input of the worksheet posted such that it triggers this Warning message. The fact that @C_R also uses Physics and the Maplesoft Physics Updates, is a red-herring and deviates the attention from the main issue; this is my understanding of the matter.

Edgardo S. Cheb-Terrab
Physics, Differential Equations and Mathematical Functions, Maplesoft

@acer 

 

Download not_related_to_physics.mw

Edgardo S. Cheb-Terrab
Physics, Differential Equations and Mathematical Functions, Maplesoft

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