## Grid computing toolbox on local multi-core server...

Is possible to operate Grid Computing Toolbox together with Maple on one local multicore machine?

If yes, what is the proper instalation/configuration procedure on Windows or Linux?

## .eps figures produced by Maple are often excessive...

Why 3D .eps figures produced by Maple 2020 are often excessively large?

So, it´s a little heavy to the viewer and to compile to PDF.

• How could we reduce the size without losing any quality?

## how to get types to show up in command completion?...

command completion (when hitting the ESC key) in Maple could be made more useful. It does not seem to support type names for example.

What shows up on the command completion window are  possible commands that start with that partial text.

It does not list other known names by Maple, such as type names and other options.

This makes it hard to use in many places, where one have to remember type names exactly instead of the system helping them by listing all possible type names that start with that string.

Is there a way around this? Will Maple next version support smarter and more complete command completion menu?

## How to get Grid Run execute in parallel?...

Hi,

I was hoping to run two procs: tgf3 and tgf4 in parallel using Grid, Run and get a faster execution time. As I understood the description of Grid Run, the first call to Grid Run will run in the background and before it is finished the second call Grid Run will start. I do not believe I have that situation in my script. I am not understanding Grid Run. How can this problem be fixed? Here is just a portion of the script using Grid Run:

Use Grid Run 0 for tgf3 and 1 for tgf4. Determine the real time and compare times. The Grid Runs do not appear to run in parallel.

rgt := time[real]();
Grid:-Run(0, ~[tgf3@op](convert(L, listlist)), 'assignto' = ans3roots);
Grid:-Run(1, ~[tgf4@op](convert(L, listlist)), 'assignto' = ans4roots);
ans3roots;
ans4roots;

GridRunTime := time[real]() - rgt;
GridRunTime := 44.074

Here is my script:

Grid_Run_2.mw

Thank you for your help.

## How do I link to help pages when creating a set of...

I have created a set of help files using the example templates. After I create the .help file and install it with my package, I can view the help pages in the help viewer. However, when I click on any link within a help page, the target page opens as a worksheet in Maple. I understand this is because I created the hyperlink with a worksheet as the target. However, I don't know where to obtain the help topic name for a help page before it has been created.  I have searched help, but can't find any applicable guidance.  Can anyone tell me how to determine the help topic name when first creating the help pages.

I have attached one of my help file worksheets.     Hlpdiracmatrices.mw

## MapToBasis/ChangeBasis -- Spherical to Cartesian...

Hello,

When I create a vector in spherical coordinates and map it to cartesian coordinates with Physics[Vectors] package as follows,

restart:with(Physics[Vectors]):
q_:=a _r + b _theta + c _phi
ChangeBasis(q_,cartesian)


I get the answer:

(a*cos(phi)*sin(theta)+b*cos(phi)*cos(theta)-c*sin(phi)) i + (a*sin(theta)*sin(phi)+b*cos(theta)*sin(phi)+c*cos(phi)) j + (-b*sin(theta)+a*cos(theta)) k

which is what I would expect.

But if I try to do that with VectorCalculus package as follows,

q := SetCoordinates(<a, b, c>, spherical)
MapToBasis(q, cartesian)


This gives

(a*sin(b)*cos(c)) ex + (a*sin(b)*sin(c)) ey + (a*cos(b)) ez

The SetCoordinates(<a, b, c>, spherical) command outputs

q:=(a) er  + (b) ephi + (c) etheta

here, a,b, and c are  depicted as the components of the vector q in spherical coordinates, but when I map to cartesian coordinates, a,b, and c are treated as if they were the coordinates in spherical coordinates rather than components-- unlike ChangeBasis in Physics[Vectors] package.

Why are these two different?

## Help for a mathematical question related bifurcati...

How I can obtain system (21) in the following pdf file?
In the first step several changes of variables are done to obtain the system (20),
then changes the variables again repeated in the neighborhood (w1 *, w2 *) to gain Eq 21.
I have 3 questuin:
1-The change of variables performed in the neighborhood (w1 *, w2 *)
for system (20) or for system (7) ???
2-What does it mean in the neighborhood (w1 *, w2 *)?
3- How did obtaun Eq (21)?

[upload link replaced by moderator, as violation of Term of Use]

[paperhub.ir]10.1016@j.neucom.2010.06.023.pdf

## Start up code error...

I am using code edit region for parameters but getting this error, can someone help me to solve this issue.

So I recently bought a new desktop with Windows 10 installed. The problem is hard to describe so I put a picture. This problem occurs randomly (Mostly occurs after I click the right button, when browsing the option in the pop-up toolbar).

When this problem happens, if I move my mouse to any toolbar which suppose to pop-up a toolbar, the pop-up toolbar wont disspear. And ultmately leads to the picture I showned above.

Sorry for the bad explaintion but it is just like I said, it is hard to describe the problem. This PC arrives around Christmas and I downloaded Maple last week. And it never have been normal. This issue also happens to NetLogo (A model simulation software).

I asked DELL's technique services and they did a remote control to help me fix the issue. However, the problem doesn't solved (They worked on this for about 3 hours). It seems the only choice I have is to reinstall the Windows.

Does anyone have met this problem or know who met it before? Please let me know and I'm really appreciate it.

## PDF export of color-bar using densityplot...

I was trying to use the idea explained in this post (), using densityplot to create a barplot. But there are several difficultes specially using new Maple that has problem with exporting plots in pdf format the same as displayed inside Maple.

The example code:

zmin := 0;
zmax := 1;
verthuebar := plots:-densityplot(z, dummy = 0 .. 1, z = zmin .. zmax, grid = [2, 10], style = patchnogrid, size = [90, 260], colorscheme = [ColorTools[Color]([0, 0, 1]), ColorTools[Color]([1, 0, 0])], style = surface, axes = frame, labels = [, ], axis[1] = [tickmarks = []], axis[2] = [tickmarks = [aList[1] = "0   ", 0.5 = typeset(alpha* ), 1 = "1    "]]);

Problems:

1- When I export the bar-plot as .eps, it shows white lines as a grid, while I don't want it and it is not the same way it is displayed at Maple!

test-1.pdf

I tried adding gridlines=false and other similar things, but had no effect. I changed 10 to 3 in grid = [2, 10], but it increases the distance of 0 and 1 from the borderies and therefore wrong numbers will be read from the color bar. Exporting the picture as .pdf doesn't have that gridlines problem, but destroys the proportions of the image, so I want to stick on the .eps one, but without those white lines.

2- How can I have 0 and 1 exactly on the start and end of the color bar and with no distance from the edges? I can use view=[0..1,0..1] at the end of the above code, but depending on the number in the grid=[2,n] that I choose, the colors may not start and end exactly at the specified colors.

## Slow interface -- large latency between keystroke ...

I'm having an issue with Maple 2020.2 classic interface being *very* slow on a new MacBook pro with Big Sur. It takes about 1 second between each keystroke and it appearing on the screen.

Is this a known bug?

## Simple interface question about default zoom level...

Hi,

I noticed that, in Maple 2020.2, the caracters seem smaller. As if the zoom had somewhat been reduced (a bit).

However, in the preferences, the default zoom level I would like is between 100 and 125% (something like 110%) (since the default zoom level is adjusted by steps of +/- 25%). I wondered if there was a way to set the default zoom level to an arbitrary value. In fact I thought it would be great to have a field instead of a list of choices, so we can choose a custom value.

Thank you

## Why Latex generates non-printable characters?...

restart;
V:=x->piecewise(0<=x and x<=a,0,infinity):
ic:=f(x,0)=piecewise(0<=x and x<=a,A*x*(a-x),0):
pde :=I*h*diff(f(x,t),t)=-h^2/(2*m)*diff(f(x,t),x$2) +V(x)*f(x,t): sol:=pdsolve([pde,ic],f(x,t)) assuming a>0; Latex(sol) gives f \! \left(x , t\right) = \left(\left\{\begin{array}{cc}A x \left(a -x \right) & 0\le x \le a \\0 & \mathit{otherwise} \end{array}\right.\right)+\left(\Mapleoverset{\infty}{\Mapleunderset{n =1}{\textcolor{gray}{\sum }}}\! \frac{t^{n} \left(\textbf{proc} (U) \\ \textbf{option} \,operator,\,arrow; \\ \mapleIndent{1} r-1 st I \ast (-1/2 \ast h\hat{~}{2} \ast m\hat{~}{-1} \ast \mathit{diff} (\mathit{diff} (U,\,x),\,x) + \mathit{piecewise} (0&lex \, \textbf{and} \, x&lea,\,0,\,infinity) \ast U) \ast h\hat{~}{-1}\\ \textbf{end\ proc};\right)^{\left(n \right)}\! \left(\left\{\begin{array}{cc}A x \left(a -x \right) & 0\le x \le a \\0 & \mathit{otherwise} \end{array}\right.\right)}{n !}\right)  Notice, non-printable characters. I think it should have been \ast there but it gives st Maple 2020.2 and Physics 897. FYI, this is what latex() command gives  latex(sol) f \left( x,t \right) = \begin{cases}Ax \left( a-x \right) & 0\leq x \land x\leq a\\0 & \text{otherwise}\end{cases} +\sum _{n=1}^{\infty }{\frac {{t}^{n} \left( U\mapsto {\frac {-i \begin{cases}0 & 0\leq x \land x\leq a\\\infty & \text{otherwise}\end{cases} U}{h}}^{ \left( n \right) } \right) \left( \begin{cases}Ax \left( a-x \right) & 0\leq x \land x\leq a\\0 & \text{otherwise}\end{cases} \right) }{n!}}  Which compiles with no problem \documentclass[11pt]{article} \usepackage{amsmath} \begin{document} $f \left( x,t \right) = \begin{cases}Ax \left( a-x \right) & 0\leq x \land x\leq a\\0 & \text{otherwise}\end{cases} +\sum _{n=1}^{\infty }{\frac {{t}^{n} \left( U\mapsto {\frac {-i \begin{cases}0 & 0\leq x \land x\leq a\\\infty & \text{otherwise}\end{cases} U}{h}}^{ \left( n \right) } \right) \left( \begin{cases}Ax \left( a-x \right) & 0\leq x \land x\leq a\\0 & \text{otherwise}\end{cases} \right) }{n!}}$ \end{document} Thank you ## The solution of a PDE... Asked by: Dear all, I have a time-fractional PDE as follows. ( denotes Caputo fractional derivative with respect to t) for alpha=1, this is a classical PDE and the exact solution is given as follows (in a book) Question: 1) for alpha=1, I want to find the L2 errors and L∞ errors in a table. 2) for alpha=0.5, Can Maple find a solution (numeric or exact)? MY TRY: (MAPLE 2020.2) download the code.mw restart: with(plots): PDE:=diff(y(x,t),t)=y(x,t)*diff(y(x,t),x$3)+y(x,t)*diff(y(x,t),x)+3*diff(y(x,t),x)*diff(y(x,t),x\$2) ;

#c is an arbitratry constant
c:=4:
exact_sol:=(x,t)->-8*c/3*(cos ((x-c*t)/4))^2;

# I selected initial and boundary conditions as follows
IBC := { y(x,0)=exact_sol(x,0),y(0,t)=exact_sol(0,t),D[1](y)(0,t)=D[1](exact_sol)(0,t),y(1,t)=exact_sol(1,t)};

numeric_sol := pdsolve(PDE,IBC,numeric);

num3d:=numeric_sol:-plot3d(t=0..1,x=0..1,axes=boxed,
color=[0,0,y]);
exact3d:=plot3d(exact_sol(x,t),t=0..1,x=0..1,axes=boxed);
display(exact3d,num3d);

pdetest(y(x,t)=exact_sol(x,t),PDE,IBC);