@Joe Riel 

"I haven't used latex so don't know how t pass it an expression sequence"

I do not think it is possible. Only way seems to be to make it a list or set, as in

restart;
expr:=alpha,beta;
latex({expr});

which gives

\left\{ \alpha,\beta \right\} 

@Kitonum 

This is strange. Why is Maple definition of LegenreQ different from Mathematica definition? And which is correct one? in Mathematica 

Table[LegendreQ[1/2 (-1+Sqrt[5]),x],{x,-0.9,0.9,.1}]

Gives

{-1.14911, -1.22789, -1.24773, -1.24077, -1.21708, -1.18105, 
-1.13481, -1.0794, -1.01521, -0.942108, -0.859547, -0.766484, 
-0.661245, -0.541228, -0.402302, -0.237519, -0.0339568, 0.23695, 
0.664454}

No complex numbers here. 

Mathematica definition is here Maple definition is here

Quick scan shows they refer to same function. But I am no expert in special functions.

Any one knows why Maple LegenredQ gives complex values? Which is the correct result? Mathematica or Maple? Or are these using different definitions for same name of the function?

Also notice that the solution to this ODE should be real in |x|<1. So I do not undestand getting a complex solution.

@ecterrab 

"Regarding the name: I understand linux handles blank spaces in filenames out-of-the-box. It is more readable in general. So unless there is a more concrete problem that you could mention, I prefer it this way."

You can ofcourse do anything you like. But the issue with spaces in file and folder names, and why it is not a good idea to use spaces in the name, is old and well known. There are many articles written about it. I just googled "spaces in filenames" and got almost half million hits. 

For example, please see what-technical-reasons-exist-for-not-using-space-characters-in-file-names  if you browse through many of the articles on this, you'll see the majority recommend against using white spaces in file names.

For readability, "Physics_Updates.maple" is just as readable, if not more, than "Physics updates.maple" and avoids all the problems.

Again, it was a suggestion.  I myself avoid spaces in file and folder names all the time. They are simply not needed and can cause problems.

@ecterrab 

Thanks,. You are correct, PackageTools:-ListInstalledPackages() does Not show the Physics package. This explains the error.

That is a good command to know about. WIll wait to try it again after next Maple update.

@ecterrab 

I must be doing something wrong. I copied your command as is, but it is saying that 

     Error, (in PackageTools:-GetProperty) package Physics Updates.maple not found

Here is screen shot

But I know I have installed this package. Here is screen shot

What did I do wrong? 

@ecterrab 

Thanks. A small suggestion on namings. It is not a good idea to have spaces in files names. For example

    PackageTools : -GetProperty("Physics Updates.maple", version);

The file name above have a space. It would be better to use underscore as in "Physics_Updates.maple". Or just "PhysicsUpdates.maple".

White Spaces in file names and folder names is not recommended and can cause problems when using the command line or on OS's such as Linux and care will be needed in working with file that have spaces in their names.

@ThU 

I have activatived initially. Then my student status was verified, and I activated again OK.

Still the problem exist, and now with Maple 2018. Once I turn off my internet, I am not able to start Maple, as it tells me it needs to activate. 

I close Maple. Connect to the internet, then open Maple again, and now it works.

This is ridiculous desktop software that requires one to be connected to the internet to use it. What if I lose my internet access or I wish not to be connected to the net? I can't use software I paid for becuase I have no internet access?

@Rouben Rostamian  

I tried this ODE in Maple 2018, it still can't solve it. I get

restart;
pde := diff(u(x,t),t) + u(x,t)* diff(u(x,t),x) = 0;
ic :=u(x,0) = PIECEWISE([0,x<=0],[1,x>0]);
pdsolve([pde,ic],u(x,t));

@Mariusz Iwaniuk 

Thank you, This is very good finding. Actually it only needed t>0 added to solve it.

restart:
pde := diff(u(x, t), t)+u(x, t)*(diff(u(x, t), x)) = mu*(diff(u(x, t), x$2));
ic := u(x, 0) =  PIECEWISE([0,x>=0],[1,x<0]);
sol := pdsolve({pde, ic},u(x,t)) assuming mu > 0,t>0;

Yes, the solution given by Maple contains unresolved integrals, but this is better than before.  I noticed also solution comes out not formatted well.

a loop? I see no loop in your "formula".

@Rouben Rostamian  

Thanks. Can I ask how did you know one needed to separate the variables by sum? Since the standard separation of variables is by HINT=`*` . Was is a trial and error, or is something one should have known before?

If I were to solve this by hand, the normal separation of variables is product not sum. 

But now I wil try `+` when pdsolve failes to solve a PDE.

Thanks

@Kitonum 

Thanks. But I am looking for symbolic solution, not numerical. I know Maple can solve this numerically ofcourse.

Do I understand correctly from the title of your post that I have a syntax error? Where is my syntax error?

@dharr 

Thanks for the hint about the Hint=`*`, but your method does not work for me. I get

Error, (in PDEtools/eval/2) numeric exception: division by zero

I copied/pasted your code as your showe it. I am using Maple 2017.3, using Physics:-Version() of `2018, March 9, 22:54 hours`

Which Maple as you using?

ALso the solution should be a Fourier series solution, as shown in screen shot in the original question.

@John Fredsted 

Why not just

number := (x::integer) -> length(x):

@acer 

sorry for the typo in the example code I posted. I corrected that later on my PC but forgot to correct it here. I just did. The warning messages still show up btw. I do not know why, even though the code works now as expected and I see the output written to the file correctly. 

read("proc.mpl");
Warning, incomplete string;  use " to end the string
Warning, incomplete string;  use " to end the string
Warning, incomplete string;  use " to end the string
Warning, incomplete string;  use " to end the string
 

It must be due to the string being on multiple lines.

Sorry you think my question was not clear. I thought It was. The reason I did not explain why I am doing, is because I did not think it is needed to answer the question and will cluter things.

I have good reason for generating Latex as I am doing it from a running program. And the question gave a very small example of the problem I am having.