MaplePrimes Questions

Hi dear mapleprime users, i have a problem in a change of varibales if the following ode. i want to use "r=R*rs,u(r)=h*u(R*rs)" variable changes in ode, how can i do that, R is a constant. tnx for the help

restart;with(Student[ODEs]):

y := (1 + diff(u(r), r))*diff(u(r), r, r) + (1 + vs*u(r)/r + (1 - vs)/2*diff(u(r), r))*diff(u(r), r)/r - (1 + (1 + vs)/(2*r)*u(r))*u(r)/r^2

(1+diff(u(r), r))*(diff(diff(u(r), r), r))+(1+vs*u(r)/r+(1/2)*(1-vs)*(diff(u(r), r)))*(diff(u(r), r))/r-(1+(1/2)*(1+vs)*u(r)/r)*u(r)/r^2

(1)

constants := constants, R:

subs(r=R*rs,u(r)=h*u(R*rs),y) ;convert(%,D)

(1+diff(u(R*rs), R*rs))*(diff(diff(u(R*rs), R*rs), R*rs))+(1+vs*u(R*rs)/(R*rs)+(1/2)*(1-vs)*(diff(u(R*rs), R*rs)))*(diff(u(R*rs), R*rs))/(R*rs)-(1+(1/2)*(1+vs)*u(R*rs)/(R*rs))*u(R*rs)/(R^2*rs^2)

 

Error, invalid input: diff received R*rs, which is not valid for its 2nd argument

 
 

 

Download change_of_variables.mw

I sort of remember there is a special syntax for setting initial condition for an ode derivative as    y'(a)=b, where and are symbols. I forgot what it is, everything I try gives error. (I thought eval was used to work for this, but can't get it to work now).

Any one knows how to set this IC?   For an example, given this ode y''(x)+y'(x)+y(x)=0 I want to solve it with the IC as   y'(a)=b where has no numerical value. Just a symbol.

For an example, using another software, it is done as follows

ClearAll[x,y,a,b];
ode=y''[x]+y'[x]+y[x]==0;
DSolve[{ode,y'[a]==b},y[x],x]

Below is my attempts in Maple. I tried eval, subs, and the normal D(y)(a)=b but none of these works when is symbol. 

I looked at help and all examples I saw use constants, as in D(y)(0)=value. 

Iam sure this is possible to do in Maple, but I forgot how. Below is worksheet.
 

interface(version);

`Standard Worksheet Interface, Maple 2024.1, Windows 10, June 25 2024 Build ID 1835466`

restart;

ode:=diff(y(x),x$2)+diff(y(x),x)+y(x)=0;
IC1:=eval(diff(y(x),x),x=a)=b;
IC2:=D(y)(a)=b;
IC3:=subs(x=a,D(y)(x)=b);

diff(diff(y(x), x), x)+diff(y(x), x)+y(x) = 0

diff(y(a), a) = b

(D(y))(a) = b

(D(y))(a) = b

dsolve([ode,IC1]);

Error, (in dsolve) found differentiated functions with same name but depending on different arguments in the given DE system: {y(a), y(x)}

dsolve([ode,IC2]);

Error, (in dsolve) found differentiated functions with same name but depending on different arguments in the given DE system: {y(a), y(x)}

dsolve([ode,IC3]);

Error, (in dsolve) found differentiated functions with same name but depending on different arguments in the given DE system: {y(a), y(x)}

#eval works if the point is actual value as in
IC1:=eval(diff(y(x),x),x=0)=b;

eval(diff(y(x), x), {x = 0}) = b

#but I want x=a in the above.


Download how_to_set_IC_point_to_symbol.mw

There is no issue for dirichlet initial condition, where  y(a)=b works. It is the  neumann one which I can't figure its syntax. So this works OK

ode:=diff(y(x),x$2)+diff(y(x),x)+y(x)=0;
IC1:=y(a)=b;
dsolve([ode,IC1]);

Singular points appear in the solution and rendering of this program. If the data does not converge when taking a short time step, what should I do if I want to cross the singular point and continue drawing the image?solve826.mw


For years I observe that package orthopoly is not considered as a package within a procedure.
Finally I have decided to ask for clarifications: Can someone explain me why procedure f generates an error?
 

kernelopts(version)

`Maple 2015.2, APPLE UNIVERSAL OSX, Dec 20 2015, Build ID 1097895`

(1)


Without any procedure

restart

H(2, x)

H(2, x)

(2)

with(orthopoly):

H(2, x)

4*x^2-2

(3)


Within a procedure

restart

type(orthopoly, package)

true

(4)

f := proc(m)
  uses orthopoly:
  H(m, x)
end proc:

Error, `orthopoly` is not a module or member

 

g := proc(m)
  orthopoly:-H(m, x)
end proc:

g(2)

4*x^2-2

(5)

 


Download meaning.mw

TIA

 

How to use for loop in the optimization function? The objective function contain piecewise function, in that case what to do?
Can anyone help me with the syntax? I am attaching the sheet below:
Question_loop.mw

Maple help pages keep getting worst with each release.

I want all input to be displayed using Maple 1D notation, so I can copy the example to my worksheet since I only use worksheet and not document (2D) mode.

So even though the first thing I do when I open help it to turn off the 

                     view->Display examples with 2D

So it is no longer checked, I still see many pages using 2D math for input. 

Here is one example ?D  page

If I copy one such input to my worksheet now it looks like this

eveything in 2D becomes ?? when I copy it.

So one can only look but not copy?

Is there any other option to make sure, really make sure, all examples have 1D as input?

The problem is that it is all not consistent. Some examples have a mix of 2D and 1D as the above page. Some are in 2D and some are in 1D.

And this is all on the same help page!

Does no one inside Maplesoft even look at their own help pages?
 

At school the teacher always said that if we have second order ode and only one initial conditions (say y'(0)=0 or y(0)=0) then the solution should have one constant of integration in it.

And if we have no initial conditions, then the solution should have 2 constants of integrations in it.

And if we have two initial conditions, then the solution should have zero constants of integrations in it.

In this example, Maple is given second order ode with one IC. But the solution it gives when asked to solve it explicit, has no constant of integration in it at all. 

When asked to solve it using implicit, then the constant of integration shows up. 

Both solutions actually verify to be fully correct using odetest. So it looks like the solution as explicit is particular solution and not a general solution.

Why is that? Why it did not give general solution when asked to solve the ode as explicit?

restart;

interface(version);

`Standard Worksheet Interface, Maple 2024.1, Windows 10, June 25 2024 Build ID 1835466`

Physics:-Version();

`The "Physics Updates" version in the MapleCloud is 1793 and is the same as the version installed in this computer, created 2024, August 25, 9:6 hours Pacific Time.`

libname;

"C:\Users\Owner\maple\toolbox\2024\Physics Updates\lib", "C:\Program Files\Maple 2024\lib"

restart;

ode:=y(x)*diff(y(x),x$2)+diff(y(x),x)^2+1=0;
IC:=D(y)(0)=1;

y(x)*(diff(diff(y(x), x), x))+(diff(y(x), x))^2+1 = 0

(D(y))(0) = 1

sol1:=dsolve([ode,IC],explicit);
 

y(x) = (-x^2+x*2^(1/2)+1/2)^(1/2)

sol2:=dsolve([ode,IC],implicit);

-(1/2)*y(x)^2+x*y(0)-(1/2)*x^2+c__2 = 0

odetest(sol1,[ode,IC]);
odetest(sol2,[ode,IC]);

[0, 0]

[0, 0]

 

 

Download why_missing_constant_of_integration_august_25_2024.mw

In calculation limit, signum and infinity appear!!!

Is this correct?

 

lim.mw

The second result is definitely wrong, but why is this? 

MmaTranslator:-FromMma("Subscript[x, 0] -> 2 (y - z) (y - z)");
                       MmaTranslator:-FromMma(

MmaTranslator:-FromMma("Subscript[x, 0] -> 2 (y - z)^2"); # should return: x[0] = 2*(y - z)^2
                      MmaTranslator:-FromMma(

The result is still wrong even if I type an explicit multiplication sign (for instance, "Subscript[x, 0] -> 2*(y - z)^2"). 

Dear all
I have an equation, I would like to dermine the exact solution, but maple return an error 

exact_solution.mw

Thank you

On a Windows 10 installation with

I get after system restart and Maple launch

followed by

What could be the cause that the update is not downloading and how to fix it?

I am trying to understand under which conditions submenus disappear.

Now I have seen that the context panel is empty when submenues disappear.

Has anybody noticed the same and are there other instances when the context panel is emtpy?

Both effects could have the same rootcause.

Here is an example:
A -> no submenu

B -> Empty context panel

C -> Menu appears inside workspace (first time I see that)

 

Update

C seems to happen when the Maple window is not maximized to the full screen. -> then the context pannel becomes empty (for some reason) -> then if the Maple window is maximized to full screen we see C. Opeing new documents do not show this when toggling between and

On donne un cercle fixe de diamètre AB, un point M variable sur ce cercle et on construit un carré de sens direct AMNP; Trouver les lieux des points N et P.
restart;
with(plots);
r := 1;
A := [-r, 0];
B := [r, 0];
M := [r*cos(theta), r*sin(theta)];
N := [r*cos(theta) - r*sin(theta), r*sin(theta) + r*cos(theta)];
P := [-r*cos(theta) - r*sin(theta), r*cos(theta) - r*sin(theta)];
c1 := `~`[plottools]*circle([0, 0], r, color = blue);
plot1 := plot(c1, color = blue);
plot2 := animate([N[1], N[2], theta = 0 .. 2*Pi], color = red, thickness = 2);
plot3 := animate([P[1], P[2], theta = 0 .. 2*Pi], color = green, thickness = 2);
display(plot1, plot2, plot3);
Would you like to improve this code so it works. Thank you.
 

Hi everyone,

I’m encountering an issue with Maple 2024 on my MacBook Air M1 (2020) running macOS Sonoma 14.6.1. Every time I try to log in to Maple Cloud from within the application, the entire program freezes and becomes unresponsive. I’ve tried restarting the application and my MacBook, but the problem persists.

Is anyone else experiencing similar issues with Maple 2024 on an M1 Mac running macOS Sonoma? If so, have you found any solutions or workarounds? I’ve checked for updates and even reinstalled the software, but the problem still exists.

Any help or advice would be greatly appreciated!

Thanks in advance!

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