@nm 
Thanks to you for your kind comments, others aware of the novelty also started using it, and with that we are having fantastic early feedback. By the way, I dislike to say it but, unfortunately, Physics is work I do alone (but for the invaluable feedback of users of the package), including Latex now. This Physics:-Latex project comprises a myriad of necessary related improvements in the File -> Export -> LaTeX (FEL) facility too, that transforms worksheets into papers. Those FEL improvements, however, are in java and cannot be distributed in the Maplesoft Physics Updates. As usual, please remember that all this Physics Updates is research activity, and as such, all or part of it may or may not be included in subsequent official releases.

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

Incidentally, for a couple of weeks, there is a new command, Physics:-Latex, included in the Maplesoft Physics Updates, that is supposed to address the "fractions issue" you are mentioning, as well as several others. The package is not finished, but I understand it already supersedes the user-level latex command, besides providing latex translation to a myriad of new things not translated by latex. Give it a try. I appreciate feedback to improve it, either to physics@maplesoft.com or here, as you prefer.

This new command may replace the old one, or remain as a Physics latex translation that additionally covers the mathematical-physics and differential geometry notation not covered by the old one.

As soon as I have some pending developments finished, I will post here clarifying what the new features (it is a long list) are.

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

@DoingMath2018 

Writing here not as a Maplesoft employee but as anyone else.

I think there is something beyond cultures that we can all understand: you can express yourself in a way that is not toxic to the reader. I realize that some things can generate anger enough for someone to express herself in aggressive mode, and in such a case some people may prefer to express themselves (instead of saving the stress impact that has in your own body). But expressing angrily basically happens after a conversation-exchange escalates, not the case of your post, where, surprisingly for me, you express yourself very aggressively right away.

The problem with that is that your anger deviates the attention completely from the contents of your post which, content-wise, is a perfectly valid opinion, even one that is partially shared by people who replied here (itsme summarized that well).

So please listen. Not listening is one of the things you are criticizing others. Don't do that. It is not good to express yourself the way you did. You can still rewrite your post removing the anger.

That said, I have comments about the contents, disregarding the toxic angrily envelope. I see the following:

• 2D-Math display issues: you seem to like the idea, but not at all the implementation. I actually have an opinion: I prefer 2D display of input versus 1D display and prefer Worksheet versus Document, as explained in this Mapleprimes reply. And also think that fixing 2D-Math display of input is of the utmost importance. 
• Plots (their display, manipulation or export to PDF / print). I agree with everyone that thinks this is of top importance, and I also agree that we can always learn - or simply raise the bar - by looking at what is implemented in other software, even freeware, when they perform better.
• Documentation: the existence of overlapping pages regarding what to use, or do when you start using Maple. This is by all means very relevant.
• Interface bugs (from cursor flickering to other stuff not mentioned): I personally think that the UI is just the most important part - it is what we use to communicate with the computer.

So, you see, other people also find these topics valid. But then your post has no examples of what you say. I realize you also think providing examples is doing beta testing for free. With due respect, it may be your anger speaking, but we know that is not true.

Providing 1 example for each of the four items above takes you maybe 1 min per example? And suffices to make your points. Moreover, we know, it is always the case that something may have escaped our attention (e.g. discovering that there exists 1D-Math display of input lines and that there exists the Worksheet mode, not just the default Document mode). That 1 example helps with that understanding too (to the benefit of not just you but also everybody reading the thread), and without undoing any of your points.

Finally, unless your post was intended only to offend (which I believe is not the case), no matter the past, you never know about the future, and maybe these examples that you can add to this post (rewritten without anger) can indeed trigger improvements in the UI - in that way turning your time-investment in this post a valuable game-changer.

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

@nm 

You are changing the question. Your original question was "what is the status of this. Is it true there is now a method to solve all these exactly and may be Maple's implementation is not in yet for this?" The answer to that: false, and Maple has the most advanced algorithms for this problem, including that the algorithms we developed represent the most advanced understanding of this type of ODE (as explained in the previous reply).

Your new question is about the solutions for constant invariant Abel equations. These are the 'directly obtained' solutions for the one you showed:

You realize that by now there are many different algorithms that include, as a subset, the case of Abel equations with constant invariants. It is an easy problem, and it is a pitty (or a shame) that some people claim they can solve "all Abel equations", to then only show how to solve them when the invariants are constant.

Regarding "how" the solutions are obtained (the formulas), most of these algorithms are explained in the odeadvisor help pages, others in papers (see ?dsolve,references) and, in particular for Abel constant invariant (regardless of whether f2 = 0), the first algorithm I saw is in Kamke's book, as explained in the page ?odeadvisor,Abel, quoting from there, first paragraph: "See Differentialgleichungen, by E. Kamke, p. 24"

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

@vv 

The routines used within the Physics package are all visible as the Physics:-Library, and they all have help page documentation, albeit behind the development, a handful of the 166 commands you see when you with(Physics:-Library) still miss a section in ?Physics:-Library.

So either you were not aware of that, or otherwise, what are you referring to with "implemented in a strange and undocumented manner"?

Also, you say "...the Physics package, where almost everything is redefined." That is inaccurate and can be misleading. In the Physics package, several commands are extended to handle more things. For example, the product operator `*` can handle non-commutative operands, and the `.` operator can handle a myriad of other situations beyond multiplying Matrix and Vector. Similar with diff, that after loading Physics can perform a myriad of differentiations not possible before loading Physics.

Again, all that is documented: there is a help page for, say, Physics:-<diff, `*`, `.`>, where everything is explained (up to what is reasonable; the pages are long).

The most important thing: besides the additional functionality provided by the package, all the results you get before loading Physics - not related to the additional functionality - you also get after loading Physics.

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

@Preben Alsholm 

That is definitely a bug in int. Your use of assuming deviated the attention at first but no: expr2 has no locals while res := int(expr2, p) contains a[5], where a is a local variable, and that is not related to the use of assuming before or after calling int:

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

@Jean-Michel Collard 

OK. Please check all these things in order to resolve the issue. Maple is always installed in the directory shown via

> kernelopts(mapledir);  # <- could you please enter this and show the output?

From what you show for libname, apparently, in your computer Maple is installed under "C:\Maths\Maple". The main libraries of the Maple system are then in the directory "lib" below kernelopts(mapledir), that would be "C:\Maths\Maple\lib".

The message you see from Physics:-Version() is telling you that the active version of Physics is found in "C:\Maths\Maple\lib" and not where you have the Physics Updates installed, which is the directory shown by

> kernelopts(':-toolboxdir' = "Physics Updates");

Expected is  "C:\Users\jm\maple\toolbox\2020\Physics Updates", or "C:\Users\jm\maple\toolbox\Physics Updates" without the 2020. So please follow the instructions in this comment I made regarding a similar question. It is key that the file override_maple.txt is present because it tells Maple that the directory should go first in the sequence in libname. 

So after following those instructions, close and reopen Maple, and input

> libname;

It should show the directory "lib" under the directory kernelopts(':-toolboxdir' = "Physics Updates"). If so, everything is correct and when you enter Physics:-Version(); it will show the latest version active. 

From there on, you should be able to get the next versions of the Updates using the icons of the MapleCloud or directly entering Physics:-Version(latest);

I hope these guidelines resolve your problem, which of course it is not "yours" but a problem in the Maple installer; I understand it is going to be fixed in a Maple 2020.1.1 to be released.

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

@DarkMath 
Yes. That is also mentioned in the help page - see ?convert,VectorCalculus, the same page opens via ?convert,PhysicsVectors.

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

@Jean-Michel Collard 
Next, install the Updates using the MapleCloud icons. Then close Maple, open Maple, and show please the output for

Physics:-Version();
libname;
 

If Version tells the update is installed but not active, please discover where is it installed (probalby under C:\Users\jm\maple\toolbox) and put all that information your next reply, thanks.

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

@tomleslie 

There is no "PhysicsUpdates installer". There is the PackageTools Maple package, which is used by the MapleCloud and other commands to install things. Unfortunately, there is an issue in PackageTools such that the 2020 directory got omitted, also in Maple 2020.0. That was not an obstacle to installing the package and had it working but, apparently, it is in 2020.1 in your case. Anyway I am glad to hear that, after inserting (manually) the 2020 subdirectory, things work as expected.

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

@tomleslie 

Well, at least we are out of the woods! :) Unfortunately, this is not something I can fix within the Updates. It would be interesting to do the following. Check your rights to the directory toolbox/2020 (make sure you have full rights) then: enter restart; Physics:-Version(708); then restart; Physics:-Version(latest). Expected: it works, first installing the previous version, then installing the latest version, and always under toolbox/2020. If so, from here in you can update, as usual, either entering 'latest' or through the MapleCloud icons. If not, there is still a problem - probably a rights issue.

Best

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

@tomleslie 

The "mserver.exe has stopped working" is clearly an issue, probably the whole issue. I know of another person having this problem, and the problem has been reported to the people who take care of it. 

Meantime, this is the structure of directory and files that I expect for Maple 2020.1:

So please create 2020 below toolbox, then move the Physics Updates directory within 2020, as you see in the image. You can get the Physics Updates.maple file downloading manually from the Maplesoft R&D Physics webpage, and you do have the version.txt from the failed installation. For the override_maple.txt, copy the one you have in Maple 2019 or previous.

That will make the Updates work and in the right place (under 2020; could you please confirm that it works) while there is a fix for these 2020.1 problems. By the way, the installation issue you are having (but for missing the 2020 directory) does not happen in Macintosh.

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

@tomleslie 

Please recall: "Then close, then reopen Maple (not just 'restart'), and input 'Physics:-Version()', everything should work. If not, then also input 'libname', and reply here showing a picture with the output of Version and libname. With that info we can figure out what is going on at your end."

I still don't see that image showing the output of Version and libname. Only with that info, obtained after closing and reopening Maple, is that I can give you an opinion of what could be going on.

Independent of that: from what you say, somehow the download is not working for you - maybe a rights issue. One alternative is for you to download the package and move the Physics Updates.mla to the expected directory. This should't be necessary but it is a workaround. I've seen another person with this crash, so maybe there is something wrong with the 2020.1 update of Maple.

In any case, this is the contents of an email I received of someone with the same problem, how he solve the rights issue:
 

"Ok, just a quick follow up... i think the issue is that the permission of the folder:
~/maple/toolbox/Physics Updates

were set to `root` - i'm not sure how or why that happened (?). 
But a moment ago, I ran maple as root, then updated physics while running a root session (it seemed to have installed the package into my normal user directly's maple folder). Then manually changed the permissions (recursively) of ~/maple. That seemed to have worked. When I run Physics:-Version(latest) now, after starting maple as a non-root user, it tells me I have the latest. "

Summarizing what I think is going on: there is a rights issue on the directory, that should fix the problem, or you can download and put the file where it should be.

Best

Edgardo

@mthkvv 

The current v.687 contains further developments, not rollbacks. Define handles `&mu;` and `~&mu;` in definitions, `&mu;`, `~&mu;` are now valid indices, mu and `~&mu;` are not considered repeated indices when in a product, only the pairs [mu, ~mu] and [`&mu;`, `~&mu;`] respectively are. All that is new. And you cannot sum over repeated indices for objects before defining them as tensors, that is old.

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

@mthkvv 

Sorry but that won't happen. As said, that would complicate the code unnecessarily: in the output, we already have excellent typesetting, so all this is about how the input looks. But for the input, as said right-click and converting to 2D-Math input achieves an even better result: a greek letter and presented as a superscript, with no ~.

The only situation where we need to handle `~&mu;` is when you are passing a tensorial equation "to define" a tensor and you want to see ~mu as a Greek letter (by typing ~mu, then pressing escape and chosing mu you will receive `~&mu;` that looks like at ~ followed by the greek leter). In that case, the right-click & convert will not produce ~mu as a superscript because at the input level (before pressing enter in a call to Define) that object is not yet a tensor, and so the index is not typeset as a tensor index (greek and superscript, while keeping its semantics equal to ~mu).

That exception is now handled since v.686 in the only place I can think it happens, which is when passing a tensorial equation to be defined using Define, as in your original example. In the latest example you posted, anyway you cannot perform a sum over repeated indices of an object that is not a tensor (will be after you press enter in that call to Define), so your example is invalid regardless of any typesetting issue.

Just try it. Type ~mu, then right-click and convert the tensorial expression to 2D Math input and you will see it working.

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