## "LieSYMGRP maple package" ...

I read the article "Approximate Symmetries and Infinite Series Symmetry Reduction Solutions to Perturbed Kuramoto–Sivashinsky Equation", and also searched out in Maplesoft website, but couldn't found. Does anyone have the package?

## No, I didn't forget to run with(Maplets[Elements])...

I have a problem in my document (MapletsDisplayError.mw) with the following four lines of code

with(Maplets[Elements]);
maplet3 := Maplet(MessageDialog(warning, "No file containing dissociation constants found.", 'onapprove' = Shutdown()));
with(Maplets[Elements]);
Maplets[Display](maplet3);

Attached are two documents.  The first contains just the lines above and works fine.  The second generates an error when run if you choose No to both dialogs, and the error appears to be with the same four lines of code (if I comment those lines I do not get an error).

ThisWorksWithoutError.mw

MapletsDisplayError.mw

pp-velocity.mw

## Get maple to insert value's when using defined var...

Hello.

I was wondering if it was possible for maple to automatically type in the values of the variables when calculating like

U:=50V

R:=10ohm

U/R=50V/10ohm=5A

U/R=5A

hope my question makes sense :D

## Why minimize returns wrong minimum?...

Let x, y, z be nonnegative real numbers. Obviously, x3+y3+z3-4xyz is not always nonnegative, since its value is -1 when x=y=z=1. But why Maple's minimize gives wrong result?

minimize(x^3 + y^3 + z^3 - 4*x*y*z, x = 0 .. infinity, y = 0 .. infinity, z = 0 .. infinity);

Attachment: MinValue.mws.

MMA's Minimize finds correct infimum:
So, can Maple always find correct exact (i.e., not just numerical) global minima (or maxima) at least for such problems with a small number of variables as well?

## Does mathematicalnotation interfere with alias ?...

When you use

restart:
with(Physics):
Setup(mathematicalnotation=true):
diff(x(t), t)


the output is $\dot{x}(t)$
When you write

restart:
alias(x=x(t)):
diff(x, t)

the output is $\frac{\partial}{\partiall t} x$

Is it possible to "mix" these two in such a way that diff(x, t) appears as $\dot{x}$ ?
Notation.mw

## plottools arrow function does not result in arrow...

Wanted to plot a vector with the arrow function

for some reason the arrow head was not created. tried changing the input so the resulting coordinat would be [10,10] insted of [725,350] this created an arrowhead on the line.

with(plots):
with(plottools):
l1 := arrow([0, 0], [725, 350], 0.1, 0.4, 0.1, arrow, color = red, legend = "Vector v");
display(l1, axes = frame, view = [0 .. 900, 0 .. 500]);



Why does it not create the arrow head happen???

## Is this a bug in StringTools:-Remove ?...

Either I am clueless (or very tired) or StringTools:-Remove is not behaving as it should (document attached)

IsThisABug.mw

## Can Maple be forced to quit upon a syntax error, w...

Suppose a have a file "test.txt" with the following single line of code (intentionally missing the "end if"):

When I run "maple test.txt" from the command line, it shows the following and quits:

> if x = 1 then print("hi");
> quit
> quit
on line 3 of "test.txt", syntax error, reserved words quit, done, or stop unexpected
> quit

But it quits with exit code 0, despite the syntax error. Is there a way to get Maple to quit with a nonzero exit code when there is a syntax error?

What I would actually like is that if Maple encounters any error at all (syntax or otherwise), the script immediately ceases execution and exits with a nonzero error code. When the error is NOT a syntax error, I can at least accomplish this by wrapping the entire script in a try/catch block. But I'm hoping there's a better way.

## How to import matplotlib in Maple's Python interpr...

I would like to be able to use python's matplotlib from Maple. I am doing the following currently

with(Python)
Start('home' = "/opt/anaconda3/lib/python3.9", 'path' = "/opt/anaconda3/lib/python3.9/site-packages")
ImportModule("matplotlib as mpl")

and the error I get back is

Error, (in Python:-ImportModule) ModuleNotFoundError: No module named 'matplotlib'
['Traceback (most recent call last):\n', '  File "<string>", line 1, in <module>\n', "ModuleNotFoundError: No module named 'matplotlib'\n"]

The string I passed into path is the directory where matplotlib seems to be located as far as I can tell. I looked this up in my IDE Spyder, but using the command print(matplotlib__file__).

UPDATE: but actually if I open a new worksheet and execute

with(Python)
Start('home' = "/opt/anaconda3/lib/python3.9", 'path' = "/opt/anaconda3/lib/python3.9/site-packages")

The error is that

Error, (in Python:-Start) unable to start Python: could not create process, mpython

So Maple isn't finding Python apparently.

I tried for 'home' also "/opt/anaconda3/bin", did not work.

## How to determine the gradient of a vector field?...

Hello guys.

How to determine the gradient of the following vector field below:

with(VectorCalculus):

with(Student[VectorCalculus]):

SetCoordinates('cylindrical'[r, theta, z]):

V:=VectorField(<omega*r, 0, z*r>)

Error, invalid input: too many and/or wrong type of arguments passed to Student:-VectorCalculus:-Gradient; first unused argument is Vector(3, [omega*r,0,z*r], attributes = [vectorfield, coords = cylindrical[r,theta,z]])

Regards,

Oliveira

## How can I redisplay the same plot with changed dat...

Working with a Document, I have a procedure which plots a graph and part of the procedure code looks like this:

with(plots) A := Array(1) A := plot(...plots two series...): display(A)

The first time the procedure is called everything is as expected.  The second time the procedure is called (with different values to be plotted), the graph is not updated and therefore does not reflect the changed data

I am thinking that maybe, each time I call the procedure, I need to somehow "reset" or "release" something at the beginning of the procedure so that the plot is recreated?

## Is there a way to recover changes lost after endin...

I was working on a document to which I had made some changes which had not been saved.  When running Evaluate Worksheet I had to end the task because I couldn't stop the evaluation.  On re-opening the document my changes were lost, not surprisingly.

Does Maple keep any temporary files anywhere from which I might be able to salvage my changes?

## Frame around expressions....

Hello guys.
Is there any way to frame the styles: Input 2D, Output 2D and Text?

Oliveira.

## Maple is giving "Error, (in fprintf) string expect...

Hello,

I am collecting my coefficients with the below code. Since it is a huge data, i just give a some partion. So I want to write u11 to a text file. But when i use this command  save u11, "u111.txt" . It is writing to text but with big blanks. I show you at the below picture. So when i put it to matlab, it is again with spaces and matlab giving errors. So how can i save my long symbolic output (you can see in picture)  to a text file without spaces. I used

fd := "C:/double/u11.txt"

fprintf(fd, "%s", u11)

fclose(fd)

But it did not work. So if you could help me, i really appreciate. My best regards.

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