Questions - MaplePrimes

why odetest gives internal Maple error on this ode...

Asked by: nm 11388

1 hour ago

0 0

Why when adding assuming positive; Maple odetest gives internal Maple error?

>	interface(version);

>	SupportTools:-Version();

>	Physics:-Version();

>

restart;

>	sol:=y(x) = 6x/(3x-2LambertW(-3/2exp(5/2x+5/6_C2)))+1/2x+1/3; ode:=x-2y(x)-1+(3x-6y(x)+2)*diff(y(x),x) = 0; odetest(sol,ode,y(x)) assuming positive;

y(x) = 6*x/(3*x-2*LambertW(-(3/2)*exp((5/2)*x+(5/6)*_C2)))+(1/2)*x+1/3

Error, (in depends) too many levels of recursion

>	odetest(sol,ode,y(x)); #removing positive it now works

Download internal_odetest_error_sept_6_2025.mw

why adding Physics:-Setup(assumingusesAssume = tru...

Asked by: nm 11388

1 hour ago

0 0

Why when adding Physics:-Setup(assumingusesAssume = true): then combine gives internal error which can not be cought?

>	interface(version);

>	SupportTools:-Version();

>	Physics:-Version();

>

restart

>	Physics:-Setup(assumingusesAssume = true):

>	A:=1/6ln(u^2+1)+1/3arctan(u)+1/6ln(u^2-3^(1/2)u+1)-1/3arctan(2u-3^(1/2))+1/6ln(u^2+3^(1/2)u+1)-1/3arctan(2u+3^(1/2)); combine(A,ln) assuming real;

(1/6)*ln(u^2+1)+(1/3)*arctan(u)+(1/6)*ln(u^2-3^(1/2)*u+1)-(1/3)*arctan(2*u-3^(1/2))+(1/6)*ln(u^2+3^(1/2)*u+1)-(1/3)*arctan(2*u+3^(1/2))

Error, (in assuming) when calling 'is'. Received: 'invalid input: (u^2+1)^(1/6)*(u^2-3^(1/2)*u+1)^(1/6) <> 0'

>	Physics:-Setup(assumingusesAssume = false):

>	combine(A,ln) assuming real;

ln((u^2+1)^(1/6)*(u^2-3^(1/2)*u+1)^(1/6))+ln((u^2+3^(1/2)*u+1)^(1/6))+(1/3)*arctan(u)-(1/3)*arctan(2*u-3^(1/2))-(1/3)*arctan(2*u+3^(1/2))

Download adding_Phsyics_makes_combine_fail_sept_6_2025.mw

Problems using solve(identity , any workarounds?...

Asked by: nm 11388

1 hour ago

0 0

I get too many internal errors using solve(identity,... even when the call is correct and all variables are listed.

The problem these internal error can not be cought by try/catch, which means the whole program crash.

Is there alternative function to use or something to check before the call is made to avoid this?

It does not look like solve(identity has been well tested by Maplesoft.

>	interface(version);

>	SupportTools:-Version();

>	Physics:-Version();

Example 1

>

restart;

>

eq:=1/8*A^2*exp(2*theta*(B+I))+1/8*exp(2*theta*(B-I))*A^2-1/4*A^2*exp(2*B*theta)-1/4*exp(theta*(B-2*I))*A*B-1/4*exp(theta*(B+2*I))*A*B+1/2*A*B*exp(B*theta)+1/4*exp(theta*(B-2*I))*A*C+1/4*exp(theta*(B+2*I))*A*C-1/2*A*C*exp(B*theta)-1/4*I*exp(theta*(B-2*I))*A+1/4*I*exp(theta*(B+2*I))*A+1/4*C^2*cos(2*theta)-1/4*C^2-1/2*C*sin(2*theta)-1/2*cos(2*theta)-1=0:
the_vars:=[A, B, C]:
solve(identity(eq,theta),the_vars);

Error, (in gcd/doit) too many levels of recursion

>

Example 2

>

restart;

>	eq:=-x^(1/2)-1/2xA^2+ABsinh(Bx)-1/2xA^2cosh(2Bx)=0; the_vars:=[A, B]: solve(identity(eq,x),the_vars);

Error, (in gcd/doit) too many levels of recursion

>

Example 3

>

restart;

>	eq:=1 = X(2cos(X)cos(x0)-Xsin(X)cos(x0)-2sin(X)sin(x0)-Xcos(X)sin(x0)-x0sin(X)cos(x0)-x0cos(X)sin(x0))(2Yln(Y+y0)+Y+2y0ln(Y+y0)+y0)/Y/(Xcos(X)cos(x0)-Xsin(X)sin(x0)+x0cos(X)cos(x0)-x0sin(X)sin(x0)+sin(X)cos(x0)+cos(X)sin(x0))/(2ln(Y+y0)+2Y/(Y+y0)+1+2*y0/(Y+y0));

1 = X*(2*cos(X)*cos(x0)-X*sin(X)*cos(x0)-2*sin(X)*sin(x0)-X*cos(X)*sin(x0)-x0*sin(X)*cos(x0)-x0*cos(X)*sin(x0))*(2*Y*ln(Y+y0)+Y+2*y0*ln(Y+y0)+y0)/(Y*(X*cos(X)*cos(x0)-X*sin(X)*sin(x0)+x0*cos(X)*cos(x0)-x0*sin(X)*sin(x0)+sin(X)*cos(x0)+cos(X)*sin(x0))*(2*ln(Y+y0)+2*Y/(Y+y0)+1+2*y0/(Y+y0)))

>	solve(identity(eq,X),[x0,y0]);

Error, (in signature) too many levels of recursion

>	solve(identity(eq,X),[x0,y0,Y]);

Error, (in signature) too many levels of recursion

Download workaround_for_solve_identity_sept_6_2025.mw

why solve(identity,...) gives internal error when ...

Asked by: nm 11388

1 hour ago

0 0

In call to solve(identity(eq,x),the_vars); if the_vars do not list every variable in the equation (other than x), then sometimes solve gives internal error.

Is this by design or is this a bug? Here is an example

>	interface(version);

>	SupportTools:-Version();

>	Physics:-Version();

>

restart;

>	eq:=-A^2exp(2Bx)+ABexp(Bx)-2ACexp(Bx)-C^2-acos(bx)^m(Aexp(B*x)+C+1)=0;

>	the_vars:=[A, B, C,m]: #all variables are listed solve(identity(eq,x),the_vars);

[[A = 0, B = B, C = -(1/2)*a-(1/2)*(a^2-4*a)^(1/2), m = 0], [A = 0, B = B, C = -(1/2)*a+(1/2)*(a^2-4*a)^(1/2), m = 0], [A = -C-(1/2)*a-(1/2)*(a^2-4*a)^(1/2), B = 0, C = C, m = 0], [A = -C-(1/2)*a+(1/2)*(a^2-4*a)^(1/2), B = 0, C = C, m = 0]]

>	the_vars:=[A, B, C]: #forget to add m variable to list, now it gives internal error variables are listed solve(identity(eq,x),the_vars);

Error, (in depends) too many levels of recursion

Download missing_variable_solve_sept_6_2025.mw

How do I fully expand an expression a polynomial w...

Asked by: jan123 45

Yesterday at 2:09 PM

0 2

How do I fully expand an expression a polynomial with a constant c and variable m ?

How get unknown after substitution by linearizat...

Asked by: salim-barzani 1605

Yesterday at 4:42 AM

0 0

i did substitution but my result is so different from the author i think he just take the linear term of theta but i didn't do that so how take just linear term of that function and find unknwon , and how afeter replacing eq(12) inside eq(11) we can remove thus exponential and find w? also i think author did a mistake which the equation 12 is theta(x,t) not Q(x,t)

>

(1)

>

(2)

>	$P := collect(eval(subs({T, T1}, pde)), exp)/exp(I(Q^2gamma`ε`+Qq)*t)$

(3)

>

(4)

>

(5)

Download steps.mw

or for this equation

steps-2.mw

Not periodic function y(x)?...

Asked by: Alfred_F 345

September 04 2025

0 10

Prove:
If a is an irrational number, then the function
y(x) = cos(a*x) + cosx is not periodic.

Further question:
Since every irrational number can be represented as the limit of a sequence of rational numbers and all software "only" works with finite representations of numbers, it would be interesting to know at what number length for a this becomes in examples apparent in the plot for y(x).

Why won't maple print more than one row of a m...

Asked by: Paul26 10

September 03 2025

2 2

I'm not sure exactly when this started but maple on one of my linux machines won't print more than one row of a matrix. I get dots like this:

Note that interface(rtablesize) is [10,10]. This happens with both maple2024 and maple2025.

On any of my other machines, maple works just fine. I have also tried deleting ~/.maple and ~/.maplesoft

internal error when using ODESteps...

Asked by: nm 11388

September 03 2025

1 0

Fyi, this looks like a bug in odesteps. I was not expecting it to give steps for this, but I do not think it should give internal error. Will report it also. It should just say not supported or something like this.

>	interface(version);

>	SupportTools:-Version();

>

restart;

>	ode:=x^2diff(y(x),x$2)+(x^2-5x)diff(y(x),x)+(5-6x)*y(x)=0; #22942.

x^2*(diff(diff(y(x), x), x))+(x^2-5*x)*(diff(y(x), x))+(5-6*x)*y(x) = 0

>	sol:=dsolve(ode);

>	Student:-ODEs:-ODESteps(ode)

Warning, cannot verify that the given particular solution, y(x) = 1+1/5*x, actually solves the corresponding homogeneous ODE, diff(diff(y(x),x),x)+1/x*(x-5)*diff(y(x),x)-(-5+6*x)/x^2*y(x) = 0

Error, (in Student:-ODEs:-ChangeVariables) the ODE, diff(diff(U(T),T),T) = 5*(T^2+6*T-5)/T^2/(5+T)*U(T)-diff(U(T),T)*(T^2+2*T-25)/T/(5+T), contains the undifferentiated dependent variable, U(T), but the transformation %3, does not

Download internal_error_ODESteps_sept_2_2025.mw

why can't Maple solve this basic first order o...

Asked by: nm 11388

September 02 2025

1 8

Any idea why Maple dsolve can't find solution to this ode? From textbook

The strange thing, it solves if it asked for implicit solution. But the default, will give no solution.

Is this a defect? Should it not have returned the book solution automatically? How is a user supposed to know the ode has a solution or not, if default call returns no solution?

>

restart;

>	interface(version);

>	SupportTools:-Version();

>	Physics:-Version();

>

restart;

>	ode:=v(x)*diff(v(x),x) = g; ic:=v(x__0) = v__0; sol:=dsolve([ode,ic]);

>

restart;

>	ode:=v(x)*diff(v(x),x) = g; ic:=v(x__0) = v__0; sol:=dsolve([ode,ic],'implicit');

>	#why did not default call return this? PDEtools:-Solve(sol,v(x))

Download dsolve_gives_no_solution_sept_2_2025.mw

Suggestion for maple flow 2025...

Asked by: FDS 215

September 02 2025

3 2

I have bought Maple Flow 2025 and trying to use it in an effective way. While doing this I noticed some little issues that could be improved.

1. When typing text it would be nice that the cursor goes automatically to the next line when at the border of chosen paper size (e.g. A4).

2. It would be nice that you could separate the containers when they overlap by using 1 button. Now you can align containers vertically but it would be nice if you can do that also horizontally.

I also have a question, is it possible to place a section in another section as you can in Maple or is this not possible?

what is issue in thus odes which not make my funct...

Asked by: salim-barzani 1605

August 30 2025

1 2

I test a lot of them but some of them make a problem i don't know i am do it in wrong way or the author did wrong i need verifying thus solution of odes specially in case 4 when we have not equal sign how use that?

and case 5 is Weierstrass elliptic function which i don't know how set up and use i think is a on kinf of odes but why they use that sign for this function?

ode-17.mw

How to make font larger in debugger? Linux 2025.1...

Asked by: nm 11388

August 29 2025

0 2

The font size in the debugger is very small.

Even if I increase the zoom in the worksheet before starting the debugger, this has no effect on the debugger.

Is there an option to use larger font for the debugger? Here is an example, this is worksheet after making the zoom 145%

And here is the debugger window. side by side with the worksheet. Notice the font in debugger do not change.

It looks even smaller on the desktop, I am using large monitor also.

Is there separate setting to change font size for debugger?

Maple 2025.1 on Linux KDE plasma, Cauchy OS (Arch based)

How can I solve this error using Product...

Asked by: sand15 912

August 29 2025

3 5

I'm struggling to construct a statistical Distribution involving Product.
This is likely a question of delayed evaluation but I'm not capable to fix it.
Can you please look to this Product_error.mw worksheet and help me fixing the issue?

Thanks in advance

there’s a way to link each curve in the animation ...

Asked by: jalal 440

August 26 2025

0 6

Hi,

I’m having fun animating a beautiful geometric shape starting from a few trigonometric functions. I’m wondering if there’s a way to link each curve in the animation to its name.