Check the help page. ?Physics:-Setup, option realobjects. Alternatively you can use Physics:-Assume. Both indicate to the system that something is real. Still, while simplify and other commands use that information more and more, some parts of the library or their subroutines were originally written for the complex domain and may not take the 'real' value of the objects into account.

In this case and in general It would help if you post the specific example you have in mind.

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

In your PDE: replace occurrences of u  by u(x, t). Then do not assign x and t to algebraic expressions as you do, because that makes things like diff(u(x,t),x) becomes wrong Maple syntax. Next input

ii := PDEtools:-Infinitesimals(PDE)

to get a sequence of infinitesimals. Then

PDEtools:-InvariantTransformation([ii], u(x,t))

That will give you the transformations that leave your PDE invariant; you will find that the one two times previous to the last one is closer to the form of the transformation you are looking for.

Finally, try

map(PDEtools:-SimilarityTransformation, [ii], u(x, t))

and you will see the more traditional similarity transformations for the given infintesimals.

In general, take a look at the help pages listed a Symmetry Commands under ?PDEtools. You realize there are more direct ways to achieve the results you mentioned, but if you prefer to go a more manual approach, produce your HINT for the infinitesimals, and send it to the PDEtools:-Infinitesimals command (see its hint option), or likewise send your hint to SymmetryTest and of course the symmetry will not cancel the symmetry PDE equations, but the command will show you what remains, and you can solve that for the variables you want (k alpha and beta in your worksheet)/

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

In the upcoming version of Maple, all maple.sty LaTeX macros that resemble an existing non-Maple LaTeX macro are, conventionally, written using the LaTeX macro name preceded by 'm'. So \moverset, \muderset, etc.

Maintaining a single copy of the code that works in both Maple 2020 as Latex, with e.g. \Mapleoverset, and the upcoming Maple 2021 as latex with \moverset, is prone to these situations you noticed; the code mapping things between releases missed \munderset -> Mapleunderset. Some people prefer to not advance this code in the Physics Updates. I think otherwise, put it there, everybody benefits from it, and we all move forward together getting feedback right away. And when you find these issues just report them so that they get fixed.

To summarize, this issue is fixed for everybody using Maple 2020 by installing the Maplesoft Physics Updates v.913 or higher.

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

A fix for this, available to everybody using Maple 2020, is within the Maplesoft Physics Updates v. 913.

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

These are all fixed and the fix available to everybody having Maple 2020 by installing the Maplesoft Physics Updates v.911 or newer.

Download latex_examples_(reviewed).mw

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

Hi

I'm giving (zoom ...) a Physics course that finishes this week, and able to adjust things in the Physics Updates mostly in connection with that course only. I gave a quick look at the LaTeX code now and understand this problem above is fixed in the Updates already there v.907. I will give a look at the other ones you are mentioning first thing after this course, probably on Monday 18, perhaps already before Friday.

ADDED NOTE JAN/17: All the above Mapleprimes links reporting Latex issues are fixed and the fixes distributed to everybody using Maple 2020 within the Maplesoft Physics Updates v.913 and newer.

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

The error message tells the problem; in one spot, after normalization, a denominator became 0. That should not interrupt the flow, though. The issue is fixed, and the fix is distributed to everybody as usual within the latest Maplesoft Physics Updates.

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

Hi

This is indeed not correct; the code fell into a mini-trap. In your example, y(x) is a factor, so there is a solution y(x) = 0 to this problem, to which would correspond F = 0 and G = 0 and there you are: a "dAlembert ODE". However, naturally not: for F = G = 0, this is not an ODE since y' disappears. Anyway, it is fixed and the fix distributed to everybody as usual within the latest Maplesoft Physics Updates.

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

Yes, there are interface changes among several other improvements in the (now also interactive) line-breaking (option breaklines), and in connection with the upcoming release of Maple 2021, where this command is called latex (replaces entirely the old one), not Latex anymore. The problem you noticed is fixed and the fix is distributed to everybody within the Maplesoft Physics Updates v.900 and newer.

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

@nm 

The infinite loop is in `series/tanh` (input tracelast after that error message and you see it). @Preben Alsholm, generally speaking, RootOf's don't mean 'wrong' or the like (If that were the case, I would not use them). RooOf is an essential piece of computer algebra. You know, only a tiny and minuscule number of expressions have an algebraic inverse that can be expressed with so few mathematical functions. That is on the way of changing with more general functions, like the Heun, Appell and etc. but we are still far away from that. So either you use RootOf, or you can do very little.

Passing the useInt option, you dodge this issue in series/tanh and get the solution to this problem.

PS: I won't be participating in Mapleprimes till Jan/15. I wish you all happy holidays.

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

There was a place where the estimated degree appeared as a fraction, which is not a problem for add, seq or mul, but the type checking of the input was too stringent. That is now fixed and the fix distributed to everybody using Maple 2020 within the Maplesoft Physics Updates v.896 and newer.

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

The indices introduced in a product of two covariant derivatives, at the time of performing the 'convert to g_' operation, collided - they should have not. That is now fixed and the fix distributed to everybody using Maple 2020 within the Maplesoft Physics Updates v.896 and newer.

PS: one more adjustment; this is resolved in v.897.

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

There was an issue, not related to ':-executeprintroutines' (the design is indeed to execute print routines, and you defined several) but related to the unexpected way you defined these routines, where, e.g. `print/_C` exists, but it is not a procedure. Keep in mind that, for the print routine's extension mechanism to work, `print/_C` needs to be a procedure, not anything else (see ?print). Anyway, a fix for that unexpected situation is distributed in the Maplesoft Physics Updates v.894.

By the way: what you tried to achieve is achievable directly using alias - I mentioned this in a previous Mapleprimes post, here is your example:

In this example, the difference with the old-latex is that the new one respects (takes into account) any alias you define.

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

I didn't peak at what is going on deeper, but this is what hangs in Maple 2020, not in previous releases:

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

Hi

What started as Physics:-Latex, evolved as user-level Latex, will probably be replacing the lowercase 'latex' command of previous releases. But this is not a Maple 2020 project, that is why there is no help page for it in the current release. This is a new project, that started a few months ago, The information you are asking is as follows (where you read latex, think the Latex distributed for Maple 2020 within the Maplesoft Physics Updates). Note these are arguments for Latex:-Settings, not for the Latex command.

• cacheresults : all results by the internal latex subroutines are cached, for performance, so the translations are computed only once. However, if you are changing things in your worksheet that affect the way things are displayed, previously cached results may prevent you to get different LaTeX translations for the same input. To avoid caching results pass "cacheresults = false".
• invisibletimes : sets the string used to represent the product operator, by default " ". That matches the default of the LaTeX typesetting system where no spacing is placed between the operands of a product, so a*b is displayed "ab". To have a small space between the operands of a product you can use invisibletimes = "\\,"
• leavespaceafterfunctionname : default value is false, if set to true no \! LaTeX negative spacing command will be placed between a function name, say F and the parenthesis \left( \right) surrounding the function's arguments.
• powersoftrigonometricfunctions : default value is mixed, other possible values are textbooknotation and computernotation. With the value mixed, "sin(x)^2" is translated to LaTeX as \sin^2 x and "sin(x + y)^2"to \sin^2(x + y)". With the value textbook, in addition, inverse trigonometric functions are translated to LaTeX with the notation that uses the name of the corresponding trigonometric function power -1, and with the value computer the translation is an exact replica of what you see displayed in the Maple worksheet.
• spaceaftersqrt : default value is true, to insert or not a LaTeX small spacing command after a square root when it is an operand of a product.
• usecolor : default value is true, so that colors in the worksheet are translated as such to LaTeX.
• useimaginaryunit : default value is the one shown by "interface(imaginaryunit)", that in Maple is the capital letter I. This setting can be used to indicate the use of a different symbol when translating to LaTeX.
• useinputlineprompt : can be true or false, to put or not a prompt at the beginning of Maple input lines when using File -> Export -> LaTeX.
• userestrictedtypesetting : default value is false; if set to true, only a restricted form of typesetting, like the one used in the input lines of the Maple help pages, is used when translating to LaTeX.
• usespecialfunctionrules : default value is true; if set to false, no typesetting for the notation of mathematical functions is used.
• usetypesettingcurrentsettings : default is false; if set two true the Typesetting rules set in the Maple worksheet are not override by latex.

In the final version, probably before the end of this month there will be a couple more of options, mainly to provide more control over the automatic linebreaking and to optionally use the CTAN LaTeX tensor package to typeset tensors (instead of the exact LaTeX translation of how you see tensors displayed in a Maple worksheet).

For all the good of this new Latex command and its settings, the most relevant thing of this project, however, is the rewritten File -> Export -> LaTeX (involves java files, cannot be distributed within the Physics Updates - for this you will need to wait for the next Maple release), in turn based on this new Latex.

In brief, with the new File -> Export -> LaTeX  (as said, not the ones you have in Maple 2020) you can produce LaTeX versions of course lessons or entire scientific papers directly in the Maple worksheet, combining the what-you-see-is-what-you-get editing capabilities of the worksheet/document with the Maple computational engine to produce mathematical results:

• This new File -> Export -> LaTeX handles equation labels that can appear in the output and also referred to within the text and the input lines. So feel free to use and refer to equation labels all-around in your worksheet.
• In the worksheet, before exporting, if you prefer, you can remove all, or selectively some, of Maple's input (the Maple output and corresponding equation labels will remain there), by respectively using the menus "View -> Show/Hide Contents -> Input," or "Edit -> Delete Element". This is particularly useful to produce LaTeX mathematical documents that entirely or partially hide their computer algebra origin.

• In the worksheet, mark with the mouse any mathematical expression written within the text using Maple syntax (e.g. Int(f(x), x)), or that appears in the Maple input and, through right-click, use "Convert To -> 2-D Math" to produce a textbook mathematical display of that expression, that will then appear as such in the LaTeX exported document.

The project has several details and the help page is relatively long. Plus, some of these features just described are not in Maple 2020, for them you will need to wait for the next release. If even so you think it is important / of value to have this help page posted here in Mapleprimes, let me know. 

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