@Carl Love 

thanks. that worked. But I wish help put the dependent variable there as well, as I was just following the help example, in this PDF file

http://www.maplesoft.com/products/maple/new_features/Maple2017/PartialDifferentialEquations.pdf

which had (page 15 for example)

pdsolve([pde,bc]);

and not

pdsolve([pde,bc],u(x,t));

And I had not noticed u(x,t) was missing, since it worked on the other examples and was not needed.

I think help should be corrected to add u(x,t) in there, just in case it is needed as in this case.

thanks for the link to the PDE examples PDF file. More examples always help. But on page 15, I see this example

When I try it on Maple 2017 on windows 7, I do not get the exact same result. I get an extra _Z1 before the sin(). Here is the screen shot

Here is the code also in plain text

restart;
pde:=diff(u(x,t),t)=k*diff(u(x,t),x$2);
bc:=u(0,t)=0,u(L,t)=0;
pdsolve([pde,bc]) assuming 0<L;

WHat happend to the extra _Z1 in the example shown in the PDF?

Also, Maple still can't solve heat pde as the above, when one or more of the boundary conditions is not homogeneous. For example, with

bc:=u(0,t)=0,u(L,t)=1;

But there is standard method to solve this by hand.  Can one expect Maple 2018 to be able to solve nonhomogeneous heat PDE?

@tomleslie 

thanks, I did not know about maplemint(). But it does not work for the proc() I have tried it on now, i get error

Error, (in maplemint/statement) exception handling is not yet supported

This seems becuase becuase I have try catch in my proc(). I've commented out the try/catch, but now I get new error

Error, (in maplemint/expression) not implemented READ

It looks maplemint() still needs more work to make it more practical to use But it still seems a like a good tool when it works.

WHat have you tried? This is not free coding service here where you post your HW and ask someone just to do it for you. You need to show what you tried and where you are stuck.

@Preben Alsholm 

But this is a sturm-Liouville ODE. There are infinite number of eigenvalues, increasing and discrete in values. Numerical solution  showed only one eigenvalue. So a numerical solution will not show the same information as an analytical solution would.  But thanks for sharing this. It useful to know maple numerical solver does this.

@tomleslie 

"not sure how you are going to deal with this :-( "

Humm,. I never said the data in the file is meant to be Maple expeessions? I simply wanted to use Maple to read the file, so I can make some changes to the data, and then save it back. These are Latex strings. For other purposes, not to be used in Maple. 

@acer Thank you! That is what I was looking for. I simply did not know or hit ImportMatrix when I was searching.

@vv 

how to put that gray box around the code in your post? I looked at all options and can't seem to see one for source code? Is it in the style or font pull down menu or somewhere else? thanks.

@tomleslie 

nice! I shortened your code a little bit by make your cylinder a proc()

with(plots):  with(plottools):
sph := sphere([0, 0, 0], 10,   color=gold, transparency=0.4):
cyl:=s->display([seq(cylinder([0,0,0], h, s*sqrt(100-h^2), color=red, strips=50),h=0..10, 0.2)], insequence):
display([sph, cyl(1), cyl(-1)],style=surface,lightmodel=light1,axes=none);
 

@Christopher2222 

sorry if my question was not clear. I was learning calling maple function, and found these 4 ways, and I was just wondering if there are variations. I mean in terms of using '' and ` ` that is all.

@Bryon 

Thank you Bryon. I verified all the data is back online now. I do not what happened either. I remember was making a reply to someone, then mapleprime seems to hang for few seconds too longer than normal, at the point it verifies the name one has to enter before clicking submit. Then I noticed all the data gone there for my account after that point.

@umeriqbal 

Why not post plain text Maple code that one can copy and paste? Do not use 2D, as it is confusing. And what does p(m.theta):=... supposed to mean? Are you trying to make a proc() in Maple?

@Preben Alsholm 

thanks. I saw these, but I had no idea that evalf(('AiryAi')(n,z))  means the same as calling different function in `evalf/AiryAi`

I thought what evalf(('AiryAi')(n,z)) meant, is calling AiryAi() and then converting it result to floating point number.   The call and naming convention in Maple is still strange to me.   Since in user code, when one does evalf(foo(x)), this does not call evalf/foo(x)? It calls evalf() with the result of foo(x). Things must be different in Maple own code for some reason.

@acer 

Thanks. I think I understand a little more but need to go over all this many more times. First, yes, I mixed the the backqute `  with the single quote '  there. I do not use Maple much and forgot it was the single ' which delays evaluation not `.

I never knew that "if" was a procedure also.  But what is the advantage of writing

`if`(3<4,foo,bar) ;
       vs

if 3<4 then
   foo;
else
  bar;
fi;

It seems to me this mixture of different styles is not good. One should stick to one way of doing things, so code is consistent. It looks like 2 different languages mixed in one. For example, in the above Maple code I posted, which is from singular() function: showstat(`singular/singular`) :

return `if`(assigned(r),r,{})

Why not write the above as normal code, like this

if assigned(r) then
   return(r);
else
   return({});
fi;

Yes, the first version is much shorter, but I feel that this mixing of using key word as procedure sometimes and as keyword other times make the code harder to follow, as the pattern keeps changing.

@taro 

Indexed variable cause problems. So I was trying to see if I can use __. For example.
with(geom3d):
L:=[[1,2,3],[3,4,5]];
seq(point( a[i], L[i]), i=1..nops(L));

Error, (in unassign/indexed) arguments of type `indexed' must refer to tables or arrays

So I am trying to avoid using indexed variables, as they work sometimes, and sometimes not.  The cat does work, yes
seq(point( a__||i , L[i]), i=1..nops(L));
also this cat
seq(point( a||i , L[i]), i=1..nops(L));