Maple 2020 Questions and Posts

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

Hi,

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 :)

nieuw.mw

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?

Strange_Error.mw 

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 : test1.mw

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.
pi_filter_osc_anal.mw

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

 

vectorcalculus_question.mw

 

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]

t-match_impedance.mw

 

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

Maple Worksheet - Error

Failed to load the worksheet /maplenet/convert/t-match_impedance.mw .
 

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.

Regards

Frank

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

Hi,

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:

with(plots);
with(ColorTools);
with(plottools);
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.

Hello,

I have lists of points of different ranges that I want to plot on the same graph. I would not want to manually cut the list for the range I want to see (there are many lists) so I thought about the view option. But there seems to be a strange behaviour of pointplot combined with view:

restart;
with(plots);
pointplot([[0.1, 0.5], [0.7, 0.7]], view = [0 .. 1, 0 .. 0.1]);

 

I would like to assign the values of basis vectors which are calculated by PlanePlot. Is there anyone who knows how to use them or how to imitate the command?

PlanePlot(z+tan(-Pi/2+alph||29)*(x*sin(-Pi/2+gam||29)-y*cos(-Pi/2+gam||29))=0, [x,y,z],showbasis):
normal vector: <-.2497, .7343e-1, 1.>
equation of plane: -.2497*x+.7343e-1*y+1.*z = 0.
point on plane nearest origin: <-0., 0., 0.>
basis vectors: <.7106e-1, .9959, -.5539e-1>, <.9678, -.5539e-1, .2457>

It looks like as below:

restart;
line := x/100 - 1/2;
wave := cos(x / 5) * sin(x / 2); ## -1 <= wave <= 1
eq:= line - wave;
r1 := solve(line < -1); ## RealRange(-infinity,Open(-50))
r2 := solve(line > 1);  ## RealRange(Open(150),infinity)
## There are 27 solutions in RealRange(-50,150)

I searched Questions.  Found many solutions.  The only one that seems to work is Student[Calculus1]:-Roots()

Is there another way to do this?

I am trying to solve a system of polynomial equations (with rational number coefficients). For this I am computing its Gröbner basis using the F4 algorithm implemented in Maple. (`Groebner[Basis]`).

As far as I understand it, the algorithms solves the problem modulo one or more prime number and later reconstructs the full (rational number) solution. Usually it only takes a handfull of primes. But in my case it by now solved the problem successfully modulo about ~300 different primes, each time doing exactly the same computation (according to the log files running with `infolevel[GroebnerBasis]:=5`).

Could somebody enlighten me what this means? In particular, can I interpret this as indication that the system of equations does have or does not have a solution?

  • My system of equations is rather large. Each individual solve modulo a prime takes half an hour on a powerful workstation pc. Other computeralgebra systems without Faugère's algorithms cant solve it at all.
  • (part of) the output can be found here: https://gist.github.com/krox/484252f075eb19edd0ac865099a564ba . The curious thing to me is that each solve behaves exactly the same. So why is maple repeating it with different primes over and over again?

Hi there, I just wanna solve a nonlinear diff equation for a 2 variables function phi.

Boundary conditions :

  1. at the wall over NACA 0012 : the derivatives wrt x & y are null
  2. for y at infinity : the derivatives wrt x & y are null

How to deal with curved body unlike the flat plate ?

Thanks for your help in advance!

This worksheet displays an ellipsoid internally tangent to the four sides of a tetrahedron.

The tetrahedron is a special case: it has a horizontal base with vertices A,B and C and its fourth vertex E is on the z axis.

However I have failed when trying to display an internally tangent ellipsoid in any other tetrahedron.

Will any tetrahedron support one or more internally tangent ellipsoids?

If so, are there conditions restricting the location of the mutual points of tangency?

Ellipsoid_in_a_tetrahedron.mw

Hello,

 

When I try to get the magnitude of the transfer function in the uploaded file, I get this error:

Error, invalid input: `simpl/abs` expects its 1st argument, a1, to be of type algebraic, but received [0.15000e8/(-0.2137457857e-6*f^2+(2.909554620*I)*f-(0.1565896548e-13*I)*f^3+0.152600e8)]
 

How do I get the magnitude and phase of this transfer function so I can plot it as a function of frequency, f?  If you can show me how to plot it, that would help a lot as well.

 

Thank you,

Maple Worksheet - Error

Failed to load the worksheet /maplenet/convert/temp.mw .
 

Download temp.mw

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