MaplePrimes Questions

Dear all

I noticed that maple is slow to calculate the inverse matrix for my problem (Attachment)

Do you have any methods to reduce time of calculation? 

Thank you

InverseMatrix.mw

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.
 

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>)

Gradient(V, [r, theta, z]);

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

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? 

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?

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

Oliveira.

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. 

A robust largescale index-1 DAE (and stiff ODE) solver has been developed in Maple.
Details about our approach are provided in a paper just submitted. 
See arxiv at
https://arxiv.org/abs/2212.02630

We encourage everyone to test these codes and report bugs. All the examples can be run with Intel's Pardiso (provided users have access to libraries) by calling DAESolverP.txt and by calling "IMPDAEP" instead of "IMPDAE". This is useful for large-scale problems. The symbolic capability and ListTools search capability of Maple are very good and can be used for developing optimization solvers as well.

I would like to know if CPU time/memory usage can be reduced significantly. In particular,  for examples 5 and 6. Some ways to contribute include

(1) Running the code in evalhf or compiled form. This may be hard.
(2) Providing options to run other parallel open-source linear solvers (eg., MUMPS).

(3) Other examples that show the use of the developed solver. We are able to solve > 100,000 DAEs.

(4) Helping in converting the code to Maple 14 or earlier (by doing sparse LU Decomposition. Just using LinearSolve will slow down the code).

 

Please avoid ~,*, etc (shortcuts) unless it improves the speed of calculation.
Thanks 
Dr. Venkat Subramanian

Download examples_1_3.mws

Download example_4.mws

Download example_5.mws

Download example_6.mws
 

DAESolver.txt

DAESolverP.txt

With  
DrawGraph(G, stylesheet = [vertexpadding = 35], showlabels = false)
I get this

But if I wish emphasize the chromatic number, with
COLORS := [red, yellow, cyan, green, coral, blue, magenta, navy, orange, pink, plum, khaki, turquoise];
cn := ChromaticNumber(G, 'col');
for i to cn do
    HighlightVertex(G, col[i], COLORS[i]);
end do;
DrawGraph(G, stylesheet = [vertexpadding = 35], showlabels = false);
I get this

I want bigger vertices, any suggestions? Thanks

> expr[[(-.684-1.08*r+6.1*r^2-2*r^3+0.36e-1*ln(10.*r)-.3*r^2*ln(10.*r))/(-1.14+1.2*r+0.6e-1*ln(10.*r)), 1.290994449*sqrt((-.1296*r+1.512*r^2-.36*r^3+6.1*r^4-2*r^5-0.72e-1*r^2*ln(10.*r)-.3*r^4*ln(10.*r)+(-.684-1.08*r+6.1*r^2-2*r^3+0.36e-1*ln(10.*r)-.3*r^2*ln(10.*r))*(.216*r-2.52*r^2+.12*r^2*ln(10.*r))/(-1.14+1.2*r+0.6e-1*ln(10.*r)))/(-1.14+1.2*r+0.6e-1*ln(10.*r)))], [(-.684-1.08*r+6.1*r^2-2*r^3+0.36e-1*ln(10.*r)-.3*r^2*ln(10.*r))/(-1.14+1.2*r+0.6e-1*ln(10.*r)), -1.290994449*sqrt((-.1296*r+1.512*r^2-.36*r^3+6.1*r^4-2*r^5-0.72e-1*r^2*ln(10.*r)-.3*r^4*ln(10.*r)+(-.684-1.08*r+6.1*r^2-2*r^3+0.36e-1*ln(10.*r)-.3*r^2*ln(10.*r))*(.216*r-2.52*r^2+.12*r^2*ln(10.*r))/(-1.14+1.2*r+0.6e-1*ln(10.*r)))/(-1.14+1.2*r+0.6e-1*ln(10.*r)))]];
> plot([seq([expr[j][], r = 0 .. 1], j = 1 .. 2)], -6 .. 6, -10 .. 10, color = [blue, blue]);
 why I am getting error in this, please help

Hi all, 

When I am differentiate the composite functions, I wanna make the output more elegant.

For example, from the following code:

restart;
A__1 := A__0 + k(e)*a__1;
diff(phi(A__1), a__1);

I define a function phi(A__1) and function A__1(a__1), and the latter is known. 

But Maple output:

D(numtheory:-phi)(A__0 + k(e)*a__1)*k(e)

I think "D(numtheory:-phi)(A__0 + k(e)*a__1)" part can be simplified into d(phi)/d(A__1).

Do you have some ideas? Thanks!

Trying to use the following question dialog

with(Maplets[Elements]);
maplet := Maplet(QuestionDialog("Is x > 0?"));
result := parse(Maplets[Display](maplet));

Displays question with Yes and No buttons but whichever button is clicked the result is always false.  This was based closely on an example from the documentation.

So, how can I tell which button was clicked.  Also, the close button could have been clicked - how should that be dealt with?

In 1D worksheet mode I can't figure out how to insert a line between a and c. 

restart

a:=1
                             a := 1

c:=3
                             c := 3


Hello guys.

Is there any way to convert a worksheet to a document and vice versa?

Regards,

Oliveira.

Hello, everyone. I have plotted a simple equation and now have the following observation regarding it.

1- How to change or control axis style mean style like bold, colour change etc?

2-  How to change or control the font, colour and style of numbers written automatically by maple while plotting on the axis (x-axis, y-axis)?

3- How to change the font, style and colours of labels?

The problem I am facing is that whenever I save or import any graph as png or jpeg and then paste it into MS word, it's quality or pixel changes and it looks very bad. is there any way to save and paste good-quality pictures into documents that means DPI?

Qaulity_Help.mw

1 2 3 4 5 6 7 Last Page 1 of 2177