Maple 2020 Questions and Posts

These are Posts and Questions associated with the product, Maple 2020

I create a table of 3D points in one worksheet and would like to use these values at a later time in a separate worksheet.

What is the simplest way to do this?




InvT := Matrix([[c^2, s^2, -2*s*c], [s^2, c^2, 2*s*c], [s*c, -s*c, c^2-s^2]])

Matrix(%id = 18446746411704779590)


T := Matrix([[c^2, s^2, 2*s*c], [s^2, c^2, -2*s*c], [-s*c, s*c, c^2-s^2]])

Matrix(%id = 18446746411704773678)


c := cos(p)



s = sin(p)

s = sin(p)


Q := Matrix([[Q11, Q12, 0], [Q12, Q22, 0], [0, 0, Q66]])

Matrix(%id = 18446746411704759470)


Q11 := E1/(-v12*v21+1); Q12 := E2/(-v12*v21+1); Q66 := G12







E1 := 0.233e12; E2 := 0.231e11; v21 := 0.2e-1; v12 := .2; G12 := 0.717e10











R := Matrix([[1, 0, 0], [0, 1, 0], [0, 0, 2]])

Matrix(%id = 18446746411704747062)


Qbar := Matrix([[Qb11, Qb12, Qb16], [Qb12, Qb22, Qb26], [Qb16, Qb26, Qb66]])

Matrix(%id = 18446746411704742726)


InvR := MatrixInverse(R)

Matrix(%id = 18446746411704745726)


eq1 := Qbar = InvT.Q.R.T.InvR

Matrix(%id = 18446746411704742726) = Matrix(%id = 18446746411704732718)


plot(Qb11, p = 0 .. 9)

Warning, expecting only range variable p in expression Qb11 to be plotted but found name Qb11






I would like to know how to make a graph like the attached. The Figure IV is showing the changes in the evolution of the rate of technological progress (a topic in economics).

I would like to make a graph exactly like the image attached where it clearly shows the name of the x- and y-axis; the name of the functions; the 45-degree line; the transition from "theta_1" to "theta_2" with the arrows, etc. (In fact, I want to have everything the same from the graph). 


I have attached a PDF document with the definition of the functions and the figure itself. I have also attached the image of the figure on this thread. 



For examples, they are two non-commutative variables x and y, and i use "Setup(noncommutativeprefix={x,y})" to define.
 As the previous results have shown that AntiCommutator(x,x)=0 and AntiCommutator(y,y)=0, so i just define Setup(algebrarules={%AntiCommutator(x,x)=0, %AntiCommutator(y,y)=0}).
When i am calculating AntiCommutator(x,y), the maple automatically simplifies the results and returns AntiCommutator(x,y)=0, as variables x and y are thought to be GrassmannParity =1 variables.

Consider two  3*3 matrix e23 and e32, the AntiCommutator of (e23, e23)=(e32,e32)=0, but the AntiCommutator(e23,e32)= e22+e33.

So how the algebrarules work and why there is the contradiction ?

The file is attached.


The command 'coeff' doesn't work.


What am I doing wrong? Seems like some unit compatibility problem when tryaing to solve simple task with momentum conservation rule...

Automatically loading the Units[Simple] subpackage

m__2 := 0.400*Unit('kg');
m__1 := 0.300*Unit('kg');
x__w := 0.700*Unit('m');

v__2p := 0.000;

v__1p := 2*Unit(('m')/('s'));


m__1*v__1p + m__2*v__2p = m__1*v__1k + m__2*v__2k;
             0.6 = (0.3 v__1k + 0.4 v__2k) Unit|-|

subs(v__2p = 0, 0.600 = (0.300*v__1k + 0.400*v__2k)*Units[Unit](s/m));
             0.6 = (0.3 v__1k + 0.4 v__2k) Unit|-|

v__1k := solve(0.600 = (0.300*v__1k + 0.400*v__2k)*Units[Unit](s/m), v__1k);
           v__1k := (-1.333333333 v__2k + 2.) Unit|-|


1/2*m__1*v__1p^2 + 1/2*m__2*v__2p^2 = 1/2*m__1*v__1k^2 + 1/2*m__1*v__2k^2;

Error, (in Units:-Simple:-+) the following expressions imply incompatible dimensions: {.1500000000*(-1.333333333*v__2k+2.)^2*Units:-Unit(J)+.1500000000*Units:-Unit(kg)*v__2k^2}

Sitting and trying find solution in help and on forum but no chance.

I hope if someone copy code into maple it will look lik on my screen. Anyway I have uploaded file and below You have screen picture.

If I remove units from variables on the top all is working like a charm.

Please help me find an error guys.





I have a complex transfer function.  I've defined everyting as "real" via:

assum := Rsrc::real, C1::real, Lp::real, C2::real, f::real, RL::real, 0 < Rsrc, 0 < C1, 0 < Lp, 0 < C2, 0 < RL, 0 < f

I'm expecting simplify to reduce the following transfer function so that the denominator is real, but I can't get it to do it:

I have every variable defined as real, so I am not sure why it won't simplify this expression.


Thank you




I am currently working on structural dynamics problem where I'am trying to obtain the dynamic response of a high-rise building.

To do so I am working in the frequency domain where I was able to find my solution and now I want to obtain the solution in the real time domain by using the inverse fourier function. 

Now the problem comes when applying the inverse fourier transform. The expression which I am trying to tarnsform is extremely long and so Maple requires a lot of time. I tried to run it but after half a day it would still be evaluating. Would there be a way to speed up this process? I attached the worksheet if you're interested.

Thanks in advance :)

This worksheet produces a very strange error.

I have examined every assignment and cannot find one which relates to the error message.

Can anyone help here? 

Hello :-)

I am trying to solve a third degree polynomial with assumptions, but I do not understand Maple's answers.

I think I am not doing it ''correctly''.

Can someone please help me understand why Maple gives me these answers and how I could get the ones that Maple gives me when I fix a value for my parameter ? Please have a look at the attached file :

I hope my questions are clear, please don't hesitate if you need clarifications.

Thank you very much for your help and your advices.

I solve for a transfer function using Syrup, and want to operate on the Real part and Imagninary parts separately.  I've added "assumes" statements for every variable:  

assume(Rsrc, real);
assume(C1, real);
assume(Lp, real);
assume(C2, real);
assume(f, real);
assume(RL, real);
additionally(0 < Rsrc, 0 < C1, 0 < Lp, 0 < C2, 0 < RL, 0 < f);


When I then do something like :

instead of gettting just the real part of the expression, I get :


as if one of the variables was still not assumed to be Real.  I'm not sure where all the '~' are coming from ---is that the issue?


I apologize, I can't insert content for some reason..., although I can add the worksheeet.

Using the VectorCalculus package in Maple 2020.2, the Jacobian does accept my target function, whereas the Hessian does not. Both the Jacobian and the Hessian need an algebraic expression for its input.

What can I do to make it work?

kind regards, Harry


After I define a Ckt (a ladder network) such as :

Ckt := [v1(4), R1(50) &+ L2(0.9600), Cp(0.8200), L1(0.5000) &+ R2(0.2000), RL(1.3430) &+ LL(0.1550)]

How would I then use the value of R1 as defined above, for example, in a subsequent calculation?

Assuming the results from Solve are in (sol,rest), how can I use R1 (defined in Ckts)as a variable  --something like:

P_R1_ave := (abs(eval(v[R1], rest))/sqrt(2))^2/Ckt[R1]


BTW, I can no longer "insert contents" .  I get the following error:

Maple Worksheet - Error

Failed to load the worksheet /maplenet/convert/ .

I have no idea what may have changed --perhaps something on our server?

I use a personal licensed copy of Maple (Maple 2020.2).  In the "help about" dialog there is a clickable box titled "Reactivate License".  Does this imply that my license is not activated?  I have not had any issues with using the software.



[Moderator: removed image of help-about dialog showing purchase code]


I have the following problem with plots in Maple 2020: I wanted to create several plots which should have the exact same size. I used the command size = [400,400] and Maple is creating a plot with that size, but Maple applies a white frame to my plots which does not have the same size in all cases (see the red mark of different length in the pictures below), so that the effective size differs, which is extremely ugly if you want to arrange several pictures in a document. So my question is

1.) How to remove this white frame, so that the efftictive picture size is actually 400x400?

2.) If 1.) is not possible, how can I adjust the frame so that it always has the same size?

My Code:

plot1 := inequal(0 <= y^3 + x^2, x = -5 .. 5, y = -5 .. 5, filledregions, color = blue, background = "Gainsboro", size = [400, 400]);
plot2 := plot(x = -5 .. 5, y = -5 .. 5, background = "Gainsboro");
ll := line([-3, 0], [3, 0]), color = blue, thickness = 5;
l := line([-3, 2], [5, 5]), color = blue, thickness = 2;
display(plot2, l, size = [400, 400]);

Thanks for your help.

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