Maple 2019 Questions and Posts

These are Posts and Questions associated with the product, Maple 2019

I want to factor large numbers, for this purpose I want to utilize multi cores on my computer.

Anyone who can help me in solving this problem?

I am utilizing Lenovo Thinkpad T440s with specifications core i7-4600 CPU @ 2.19 GHz.

In addition I would like to ask if anyone can help me in integrating GPU's with Maplesoft 2019 for factorization.

 

I am having a cluster of 64 GPU's i.e. AMD RX-460.

 

Any help in this regard will be appreciated.

 

I am using a maple workbook to develop, test, and install a package I am developing.  Several days ago, I noticed that the workbook was not updating the package to reflect the most recent versions of my source code (.mpl). I initially assumed the problem caused by some unintentional change I made to the file, but in the end I found there is a general problem with the URIs in the maple workbook. Everything worked in 2019.1 and I hadn't made any changes after I updated to 2019.2.1.

To confirm the problem, I created a new directory(in fully updated Windows 10 ) and copied my source file into the directory. Then I created a worksheet in maple and saved it into the directory as xx.mw. Using the Navigator panel I then saved the worksheet as a workbook creating xx.maple in the directory.  I then tried to attach the mpl file to the workbook.  In the Navigator menu, the item "attach a file" is unavailable( greyed out).  This is also the case in any of the other earlier workbooks I have created.  I have confirmed the problem is not affecting worksheets because I was able to read my mpl file into a worksheet and load the module using a with(modulename) command.

Please advise.

Hey there

I have noticed that after some time, Maple freezes and says in the bottom left corner that it is "evaluting" when I  copy something. This is becoming unbearable, as it makes every assignment take a lot longer. Why is this happening, and how can I prevent it?

Hi, 

This is a question more or less related to this one Is it possible to define variables with unusual na... but I think it's better to open a new thread. If some think otherwise, please feel free to displace it to the link above.

I want to relabel the vertices of a graph by using special characters.
It happens that this works perfectly if I do not impose the style of the drawing but that it doesn't if I set, for instance, spring=style.
In the attached file you will see that the subsitution of the old vertex names by the new ones doesn't work if apply it directly on the many operators of the PLOT command contains.

Is this behaviour fixed in more recent versions of Maple or it's still present?


Strange-Behaviour-with-SpringStyle.mw

The Library:-RedefineTensorComponent in the physics package has got some serious problems, I guess in the update. It is not assigning the components at the right location for a tensor of rank 4 and above. It is working for tensors of rank 1, 2 and 3. Can someone please look into the issue and help out?

I am attaching the code with an example to indiacate the problem. Redefine.mw

Hi there!

Sorry to ask, but I don't know how I can solve it in a smart way. I want to take the covariant derivative of a specific vector, whose components are specifically defined, which can be constant or some functions of the coordinates. But, as soon as I define that specific vector, the covariant derivative fails to compute, saying there are "too many levels of recursion". Let me show what I mean.

I have these two attempts to get this:

 

First attempt

 

restart

with(Physics)

Setup(mathematicalnotation = true)

Coordinates(X = spherical)

{X}

(1.1)

Parameters(k)

{k}

(1.2)

Setup(metric = {(1, 1) = a(t)^2/(-k*r^2+1), (2, 2) = (a(t)*r)^2, (3, 3) = (a(t)*r*sin(theta))^2, (4, 4) = -1})

[metric = {(1, 1) = a(t)^2/(-k*r^2+1), (2, 2) = a(t)^2*r^2, (3, 3) = a(t)^2*r^2*sin(theta)^2, (4, 4) = -1}]

(1.3)

Define(b[mu])

{Physics:-D_[mu], Physics:-Dgamma[mu], Physics:-Psigma[mu], Physics:-Ricci[mu, nu], Physics:-Riemann[mu, nu, alpha, beta], Physics:-Weyl[mu, nu, alpha, beta], b[mu], Physics:-d_[mu], Physics:-g_[mu, nu], Physics:-Christoffel[mu, nu, alpha], Physics:-Einstein[mu, nu], Physics:-LeviCivita[alpha, beta, mu, nu], Physics:-SpaceTimeVector[mu](X)}

(1.4)

NULL

Define(Db[nu, mu] = D_[nu](b[mu](X)))NULL

{Physics:-D_[mu], Db[nu, mu], Physics:-Dgamma[mu], Physics:-Psigma[mu], Physics:-Ricci[mu, nu], Physics:-Riemann[mu, nu, alpha, beta], Physics:-Weyl[mu, nu, alpha, beta], b[mu], Physics:-d_[mu], Physics:-g_[mu, nu], Physics:-Christoffel[mu, nu, alpha], Physics:-Einstein[mu, nu], Physics:-LeviCivita[alpha, beta, mu, nu], Physics:-SpaceTimeVector[mu](X)}

(1.5)

Define(b[mu] = [0, 0, 0, beta], redo)

{Physics:-D_[mu], Db[nu, mu], Physics:-Dgamma[mu], Physics:-Psigma[mu], Physics:-Ricci[mu, nu], Physics:-Riemann[mu, nu, alpha, beta], Physics:-Weyl[mu, nu, alpha, beta], b[mu], Physics:-d_[mu], Physics:-g_[mu, nu], Physics:-Christoffel[mu, nu, alpha], Physics:-Einstein[mu, nu], Physics:-LeviCivita[alpha, beta, mu, nu], Physics:-SpaceTimeVector[mu](X)}

(1.6)

Db[]

Db[mu, nu] = Matrix(%id = 18446746372997772822)

(1.7)

beta := proc (X) options operator, arrow; b0 end proc``

proc (X) options operator, arrow; b0 end proc

(1.8)

Define(b[mu] = [0, 0, 0, beta], redo)

{Physics:-D_[mu], Db[nu, mu], Physics:-Dgamma[mu], Physics:-Psigma[mu], Physics:-Ricci[mu, nu], Physics:-Riemann[mu, nu, alpha, beta], Physics:-Weyl[mu, nu, alpha, beta], b[mu], Physics:-d_[mu], Physics:-g_[mu, nu], Physics:-Christoffel[mu, nu, alpha], Physics:-Einstein[mu, nu], Physics:-LeviCivita[alpha, beta, mu, nu], Physics:-SpaceTimeVector[mu](X)}

(1.9)

Db[]

Error, (in index/PhysicsTensor) too many levels of recursion

 

````

Second attempt

 

restart

with(Physics)

Setup(mathematicalnotation = true)

Coordinates(X = spherical)

{X}

(2.1)

Parameters(beta, k)

{beta, k}

(2.2)

Setup(metric = {(1, 1) = a(t)^2/(-k*r^2+1), (2, 2) = (a(t)*r)^2, (3, 3) = (a(t)*r*sin(theta))^2, (4, 4) = -1})

[metric = {(1, 1) = a(t)^2/(-k*r^2+1), (2, 2) = a(t)^2*r^2, (3, 3) = a(t)^2*r^2*sin(theta)^2, (4, 4) = -1}]

(2.3)

Define(b[mu])

{Physics:-D_[mu], Physics:-Dgamma[mu], Physics:-Psigma[mu], Physics:-Ricci[mu, nu], Physics:-Riemann[mu, nu, alpha, beta], Physics:-Weyl[mu, nu, alpha, beta], b[mu], Physics:-d_[mu], Physics:-g_[mu, nu], Physics:-Christoffel[mu, nu, alpha], Physics:-Einstein[mu, nu], Physics:-LeviCivita[alpha, beta, mu, nu], Physics:-SpaceTimeVector[mu](X)}

(2.4)

``

Define(Db[nu, mu] = D_[nu](b[mu](X)))``

{Physics:-D_[mu], Db[nu, mu], Physics:-Dgamma[mu], Physics:-Psigma[mu], Physics:-Ricci[mu, nu], Physics:-Riemann[mu, nu, alpha, beta], Physics:-Weyl[mu, nu, alpha, beta], b[mu], Physics:-d_[mu], Physics:-g_[mu, nu], Physics:-Christoffel[mu, nu, alpha], Physics:-Einstein[mu, nu], Physics:-LeviCivita[alpha, beta, mu, nu], Physics:-SpaceTimeVector[mu](X)}

(2.5)

Define(b[mu] = [0, 0, 0, beta], redo)

{Physics:-D_[mu], Db[nu, mu], Physics:-Dgamma[mu], Physics:-Psigma[mu], Physics:-Ricci[mu, nu], Physics:-Riemann[mu, nu, alpha, beta], Physics:-Weyl[mu, nu, alpha, beta], b[mu], Physics:-d_[mu], Physics:-g_[mu, nu], Physics:-Christoffel[mu, nu, alpha], Physics:-Einstein[mu, nu], Physics:-LeviCivita[alpha, beta, mu, nu], Physics:-SpaceTimeVector[mu](X)}

(2.6)

Db[]

Error, (in index/PhysicsTensor) too many levels of recursion

 

````

``

On my first attempt, expression (1.7) is almost fine, but β is supposed to be constant (and a function of "t" in the future), so I set it as a constant function. But then it causes that problem. Therefore, on my second attempt, I tried to set β as a parameter since the beginning, but it was no good either.


If I were to take the covariant derivative as "D_[nu](b[mu])" (without the "(X)"), it would not have that specific problem, but would not be a good solution, since the covariant derivative would discard the partial derivative of b[mu] and, if it would have some dependence on the coordinates, it would give a wrong result.


The only way it seems to work is by defining the tensor "Db[mu,nu]" explicitly as "d_[mu](b[nu](X)) - Christoffel[~alpha, mu, nu]*b[alpha]". (It seems that the problem comes from that "(X)" next to "b[alpha]" in the connection term.) But that would be an awful way to circumvent the problem. Isn't there any better way to get this?


Can someone help me with this, please?


Thanks for any help!

 

Download Cov._derivative_of_a_specific_vector.mw

 

How can add a PNG within a text section of a Maple Worksheet without having the image appear with a black background?

Does Maple have an alpha channel or transparency setting that must be toggled for this to work?

Maple 2019
macOS 10.14.6

I am added pictures from the clipboard via drag+drop.

(Yes, I know that I can use JPEG without this problem and that is NOT my question).

--
JJW

Hi everyone, I have a problem in the code solving coupled partial differential equations. I could not find out the solution. Please help me out with this. Find the code in the attachment.

Hello,

a follow up question.

I am solving some overdetermined system of ODEs in cylindrical coordinates r,phi,Z. I obtain some equations of the following type:

(diff(_F1(phi, Z), phi)*r + diff(diff(s_r(phi, Z), phi), phi))/r = -s_r(phi, Z)/r

As can be seen, the differentiated functions do not depend on r, which is an independent variable. Thus, the correct solution is to separate the equation and have 

_F1(phi,Z)=_F1(Z), s_r(phi,Z)=s_r(Z).

By using dsolve, I always obtain a solution containing r.

A similar problem that does no contain derivatives is solved by solve/identity.

Is there something similar for dsolve?

EDIT: I again put here more info and file. I solve some overdetermined system of differential equations.

[diff(s_r(r, phi, Z), r) = 0, diff(s_r(r, phi, Z), phi) = -diff(s_phi(r, phi, Z), r)*r^2,
diff(s_Z(r, phi, Z), r) = -diff(s_r(r, phi, Z), Z), diff(s_phi(r, phi, Z), phi) = -s_r(r, phi, Z)/r, 
diff(s_Z(r, phi, Z), phi) = -diff(s_phi(r, phi, Z), Z)*r^2, diff(s_Z(r, phi, Z), Z) = 0, 
diff(m(r, phi, Z), r) = s_Z(r, phi, Z)*B_phi(r, phi, Z) - s_phi(r, phi, Z)*B_Z(r, phi, Z),
 diff(m(r, phi, Z), phi) = s_r(r, phi, Z)*B_Z(r, phi, Z) - s_Z(r, phi, Z)*B_r(r, phi, Z),
 diff(m(r, phi, Z), Z) = s_phi(r, phi, Z)*B_r(r, phi, Z) - s_r(r, phi, Z)*B_phi(r, phi, Z), 
s_r(r, phi, Z)*diff(W(r, phi, Z), r) + s_phi(r, phi, Z)*diff(W(r, phi, Z), phi) + 
s_Z(r, phi, Z)*diff(W(r, phi, Z), Z) = 0]

After some time, I arrive at the equation in the original question. So the independance of the other functions on r is the consequence of the other equations.

Here is the file (shortened): mwquestion2.mw

This is another problem I just found in Maple 2019.2 on windows 10. professional.

I wanted to close Maple, so did  File->Exit 

 

But Maple did nothing. It did not close.  Also Alt-F4 did not close Maple. I had to click on the little X on top right corner of the open window to close Maple.  

In earlier version this used to work to close Maple.

Do others see this as well?  To reproduce, simply start Maple, and do File->Exit.

Here is a movie also

 

This may be a bug.  In Maple 2019.0

plot3d(x^2+y^2)

Now grab the graphing window and drag to adjust it's size.  It doesn't adjust it's size until you let go of the mouse button.

I have a .mapleinit file that amongst other things sets libname so my own packages are accessible and can be loaded using with(). Imagine my surprise when I found that a maple program that ran half an hour ago on Maple2019 bombed when it did not find its package. Closer investigation indicates that maybe .mapleinit is only searched for in currentdir()??

The updated Maple is `Maple 2019.2, APPLE UNIVERSAL OSX, Oct 30 2019, Build ID 1430966`

The old one is gone :-(. It was Maple2019.0. I should add that on this system, Maple is installed on an administrator account that is not my user account (luckily I have access to that). I am running macOS 10.14.6 Mojave.

I verified my older Maples still work as before.

Has anyone else seen this behaviour?

Mac Dude.

Edit: I need to be more specific here: When I double-click a worksheet (.mw file) then currentdir() will be set to the directory the .mw file is in. This has been long-standing Maple behaviour. But then currentdir() does not cover the home directory where .mapleinit sits. As a result, a blank sheet finds my .mapleinit whereas my files (that habitually I open with double-click or drag-drop) do no longer run the .mapleinit file.

 

Hello people :) 

As the captian says, im trying to remove an old task i've made.
But i get this:

Error in Get, invalid object [_XML_reply_data_get("reference" =
"_Maplets_reference_12","parameter" =
"value",_XML_content("Task,UserTasks,Nyops",&Entity "#xc3",&Enity
"#xa6","tning"))]

And i have no idea what it is, but it won't erase my task :'D

Thanks a bunch in advance! 

Have a great weekend you all
Best regards Lucas :)

A few seconds after calling up Help starts zucking araound and the whole computer then freezes. Ctrl-Alt-Delete doesn't work, hard reset required. Very funny. Am I alone?

 I'd like to get all at most 15 vertices Non-isomorphic  connected  bipartite graphs. One way is to use the function NonIsomorphicGraphs(k, output = graphs, outputform = graph, restrictto = connected).

with(GraphTheory):

k:=8;
s1:=[NonIsomorphicGraphs(k,restrictto = connected,output=graphs,outputform=graph)]:
bipartitegraph:=select[flatten](x->IsBipartite(x)=true, s1):
nops(bipartitegraph);

But when k=9, it is slow, I doubted that the code 

By Checking out the encyclopedia,http://oeis.org/A033995 , we knew the following number of bipartite graphs datas of , at most 14, they are not many(the datas contain  no-connected conditions)

 

so I read the help document about  

awesome.

Ps: I know  in SageMath  we can get all bipartite graphs quikly even though n>=10  by  using the 

for g in graphs.nauty_geng('-c -b 10 -g'):
 
But I hope it can be realized in Maple. 

Thanks!

 

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