Unanswered Questions

This page lists MaplePrimes questions that have not yet received an answer

Consider the following worksheet (perhaps it is better to download the worksheet and execute since the contents below aren't showing the commands used to plot the last two plots).


 

NULL

T = log(R)/(a+b*log(R))^2

plot(log(R)/(-1.16+.675*log(R))^2, R = 1000 .. 30000)

 

NULL

10^log[10](T) = log(R)/(a+b*log(R))^2

NULL

log[10](T) = log[10](log(R)/(a+b*log(R))^2)

NULL

w = log[10](z/(b*z+a)^2)

w = ln(z/(b*z+a)^2)/ln(10)

(1)

NULL

plot(log[10](z/(-1.16+.675*z)^2), z = log(1000) .. log(30000))

 

NULL

``

NULL

plots:-loglogplot(log(R)/(-1.16+.675*log(R))^2, R = 1000 .. 30000)

 

NULL

 

My question is about making a loglog plot of the equation

for R between 1000 and 30000.

 

The second to last plot is of w as a function of z, as in the last equation below

and the plot command is (where I have subbed in a=-1.16 and b=0.675)

In the second to last plot, of course we have negative values of w. If we were to consider the underlying values of T, they would never be negative of course.

The last plot is the command

I think this last plot is what I want (though I am not sure because I am not totally sure what plots:-loglogplot is doing).

 

My question is how to obtain this loglog plot manually. That is, I want the axes to show values of R on the x axis and T on the y axis (just like a usual loglog plot shows).

In other words, how to go from the second to last plot to the same plot but showing the corresponding R and T values instead of z and w.


 

Download loglog.mw

Dear all

I would like to get the solution of a system : pde with boundary and initial condition. Everything well coded, but the code does not return the solution 

sol_heat.mw

 

Thanks for your help 

 

Hi, I'm looking to create a discovery activity to introduce the cosine . Any ideas for using Maple components with a slider to vary the position of a point on a line while displaying distances and their ratios? Thank you

Doc2.pdf

Can anyone assist with this error please?

#Clear memory and load package.
restart;  
with(LinearAlgebra):

#Initialise variables,matrices and vectors.
b:=<<18>,<-2>>:
c:=<<1>,<1>>:
i:=0:
P:=<1.08,1.37,1.56,1.61>;
t:=<5,10,15,20>;
tol:=1e-6:

#Initialise Gauss-Newton matrices.
n:=Dimension(t):
f:=Matrix(n,1):
J:=Matrix(n,2):

#Display initial parameter values.
printf("Gauss-Newton Method\n");
printf("-------------------\n");
printf("Before iterations,A = %f and B = %f\n",b(1),b(2));

#Perform the Gauss-Newton method.
while max(abs(evalf(c)))>tol do
  i:=i+1;
  for r from 1 to n do
     f(r,1):=evalf((In(b(1)+t[r])+b(2))-P[r]);
     J(r,1):=evalf(1/b(1)+t[r]);
     J(r,2):=evalf(1);
end do;
c:=Multiply(MatrixInverse(Multiply(Transpose(J),J)),Multiply(Transpose(J),f));
b:=b-c;
printf("After iterations %d, A = %f and B = %f\n",i,b(1),b(2));
end do:

Vector(4, {(1) = 1.08, (2) = 1.37, (3) = 1.56, (4) = 1.61})

 

Vector[column](%id = 36893488152076174028)

 

Gauss-Newton Method
-------------------
Before iterations,A = 18.000000 and B = -2.000000
After iterations 1, A =

 

Error, (in fprintf) number expected for floating point format

 

NULL

Download Asst_3_Q4b.mw

can you do groupwork on a single documet 

Dear Colleagues,

I wish to use plot3d to the attached code but always encoutered error. However, pointplot3d runs perfectly. Please I need your assistance in this regards.

Thank you all and best regards.K2_Problem_2_two_body_kepler_e=0.mw

I have been having problem in solving this question because of the 'Whittaker'.

Can anyone please asist me how to integrate below problem with the 'Whitaker?

f := exp(-1.5*t)*(GAMMA(2)*t^(2-alpha)/GAMMA(3-alpha)-t^(1-alpha)/GAMMA(2-alpha)+t^2-t);
               /   (2 - alpha)        (1 - alpha)           \
               |  t                  t                 2    |
   exp(-1.5 t) |---------------- - ---------------- + t  - t|
               \GAMMA(3 - alpha)   GAMMA(2 - alpha)         /
int(f, t);
 

2.^(3.-1.*alpha)*3.^(alpha-3.)*(t^(-.5000000000*alpha)*3.^(-.5000000000*alpha)*2.^(.5000000000*alpha)*(alpha-3.)*(-2.+alpha)*exp(-.7500000000*t)*WhittakerM(-.5000000000*alpha, -.5000000000*alpha+.5000000000, 1.500000000*t)/(3.-1.*alpha)+t^(-.5000000000*alpha)*3.^(-.5000000000*alpha)*2.^(.5000000000*alpha)*(1.500000000*t-1.*alpha+2.)*(alpha-3.)*exp(-.7500000000*t)*WhittakerM(-.5000000000*alpha+1., -.5000000000*alpha+.5000000000, 1.500000000*t)/(3.-1.*alpha))/GAMMA(3.-1.*alpha)-1.*2.^(2.-1.*alpha)*3.^(-2.+alpha)*(t^(-.5000000000*alpha)*3.^(-.5000000000*alpha)*2.^(.5000000000*alpha)*exp(-.7500000000*t)*WhittakerM(-.5000000000*alpha, -.5000000000*alpha+.5000000000, 1.500000000*t)+t^(-.5000000000*alpha)*3.^(-.5000000000*alpha)*2.^(.5000000000*alpha)*(-2.+alpha)*exp(-.7500000000*t)*WhittakerM(-.5000000000*alpha+1., -.5000000000*alpha+.5000000000, 1.500000000*t)/(2.-1.*alpha))/GAMMA(2.-1.*alpha)+.1481481481+(0.9876543210e-1*(-6.750000000*t^2-9.*t-6.))*exp(-1.500000000*t)-(.2222222222*(-2.-3.*t))*exp(-1.500000000*t)

I clicked on the author's page link and was redirected to front page instead. Does this link work? Why does it not work for me?

How to define constants - MaplePrimes

I can import maple, but I get an error when importing namespace/symbols:

import maple.namespace as mpl

Hi!

I'm having problems with my maple not saving. I get no error message and no windows pop up.
The error occurred after the summer holidays in Maple 2022. I use Windows 11, everything is up to date. Have no Anti-virus programs.

  I have tried the following after I discovered the error:
- To install Maple 2023
- Uninstall and delete all maple folders, then reinstall Maple 2023
- Pressed Ctrl + s
- Press "Save as..."
- Pressed on the floppy disk/save icon
- Restarted computer and updated windows
- Run Maple as administrator

The only thing I can be allowed to do is:
- Ctrl + p
- Print to PDF/printer

Really hope you can help!

I don't know where my last exchange with @mz6687  has been moved (not to the initial question  https://www.mapleprimes.com/questions/237066-Determinant-The-System-Hangs for what I see).
Nevertheless here is the reply I was sending to @mz6687  which ended with the message "Page not found".
Are_you_ok_with_that.mw

Could the one who moved the question meanwhile be so kind as to attach this reply?
TIA

Hi,

I want the T2 code to run like T1, but it doesn't, what's the reason?

T1.mw

T2.mw

For some of the users with eye problems like me, the white canvas is burning eyes out of sockets as the monitor needs to be close up. Even turning down the intensity do not work especially since all other applications on Linux can be configured to have a dark-theme, but NOT Maple it seems.

What is the reason for this resistance from Maple Developers to just ram this white canvas down our throats verion after version.

Users have been asking since about Maple 11 to change  this.

I mean, Maple is not exactly cheap, which would have been an excuse, and is formidable intellectual software, so "ability" should not be a problem

However am I to believe that just changing the canvas color, turns out to be  a serious intellectual challenge for developers ?

Google yields such custom canvas request spanning more than a decade, but users arrive at crickets and a dead end.

Please be kind and give us a customizable canvas or any DARK theme of your choice for users with visual challenges and the lots of normal users who also want a custom canvas color or dark theme. It is overdue.

At the moment I use the cumbersome table-solution with a gray background, which helps some, but it is clunky and no alternative for long term use as the window and bars itself are still white and distracts and defeats the objective somewhat.

`c₁₁`, `c₁₂`, `c₁₃`, `e₃₁`, `c₆₆`, `c₄₄`, `e₁₅`, rho, `&varepsilon;₁₁`, `&varepsilon;₃₃` = constants;
`U₁` := unapply(`U₁`(t, x, y, z), x, y, z, t);
`U₂` := unapply(`U₂`(t, x, y, z), x, y, x, t);
`U₃` := unapply(`U₃`(t, x, y, z), x, y, z, t);
phi := unapply(phi(t, x, y, z), x, y, z, t);

PDE1 := `c₁₁`*Diff(`U₁`, y, y) + `c₁₂`*Diff(`U₂`, x, y) + `c₁₃`*Diff(`U₃`, x, z) + `e₃₁`*Diff(phi, x, z) + `c₆₆`*Diff(`U₂`, x, y) + `c₆₆`*Diff(`U₁`, y, y) + `c₄₄`*Diff(`U₃`, x, z) + `c₄₄`*Diff(`U₁`, z, z) + `e₁₅`*Diff(phi, x, y) = rho*Diff(`U₁`, t, t);

PDE2 := `c₆₆`*Diff(`U₂`, x, y) + `c₆₆`*Diff(`U₁`, y, x) + `c₁₂`*Diff(`U₁`, x, y) + `c₁₁`*Diff(`U₂`, y, y) + `c₁₃`*Diff(`U₃`, y, z) + `e₃₁`*Diff(phi, z, y) + `c₄₄`*Diff(`U₃`, y, z) + `c₄₄`*Diff(`U₂`, y, z) + `e₁₅`*Diff(phi, y, z) = rho*Diff(`U₂`, t, t);


PDE3 := `c₄₄`*Diff(`U₃`, x, x) + `c₄₄`*Diff(`U₁`, z, x) + `e₁₅`*Diff(phi, y, x) + `c₄₄`*Diff(`U₃`, y, y) + `c₄₄`*Diff(`U₂`, z, y) + `e₁₅`*Diff(phi, y, y) + `c₁₃`*Diff(`U₁`, x, z) + `c₁₃`*Diff(`U₂`, y, z) + `c₃₃`*Diff(`U₃`, z, z) + `e₃₃`*Diff(phi, z, z) = rho*Diff(`U₃`, t, t);

PDE4 := `e₁₅`*Diff(`U₃`, x, x) + `e₁₅`*Diff(`U₁`, y, x) - `&varepsilon;₁₁`*Diff(phi, x, x) + `e₁₅`*Diff(`U₃`, yx y) + `e₁₅`*Diff(`U₂`, z, y) - `&varepsilon;₁₁`*Diff(phi, y, y) + `e₃₁`*Diff(`U₁`, y, z) + `e₃₁`*Diff(`U₂`, y, z) + `e₃₃`*Diff(`U₃`, x, z) - `&varepsilon;₃₃`*Diff(phi, z, z) = 0;

pds := [PDE1, PDE2, PDE3, PDE4];
sol := pdsolve(pds);

i was solving the above set of pde. but it was showing the following errors,

Error, (in U₁) too many levels of recursion
Error, (in unapply) variables must be unique and of type name
Error, (in U₃) too many levels of recursion
Error, (in phi) too many levels of recursion
Error, (in pdsolve/sys/info) required an indication of the solving variables for the given system

can anyone help me?

In help(EllipticF): Why is the parameter k not called “the modulus of the elliptic function” as in the definition of the inverse Jacobi functions in help(InverseJacobiPQ)?

Instead, it is called “the parameter” which can be confused with the parameter m=k^2 used in other notations (which is refered to "a parameter m" in the EllipticF help page).

Is there a reason for this, or should the parameter definitions of the first, second and thrid elliptic integrals not be aligned with the parameter definitions of the Jacobi functions and their inverses?

DLMF for example defines k as modulus for both, the Elliptic Integrals and the Jacobian Elliptic Functions.

A user who wants to transfer an expression from a different notation to Maple might misinterpret parameters.

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