I am trying to put an annotation  (dimension of a distance) into a plot.

Any hints about what would the best way to do that?

I do not know if this is new error in 2023. But solve gives this strange error first time it is called. Second time the error goes away.

Any workaround possible and why does it happen? It happens when kernelopts('assertlevel'=2): is set. But I need to have this set all the time.     Same problem when using PDEtools:-Solve. I can't even trap this error since it is internal. So program crash and no way to continue.

restart;
interface(warnlevel=4):
kernelopts('assertlevel'=2):
eq:=exp(x)*sin(y(x))-3*x^2+(exp(x)*cos(y(x))+1/3/y(x)^(2/3)) = 0;
solve(eq,y(x));

Error, (in SolveTools:-CancelInverses) assertion failed, simplify should not leak _Z variables out from RootOfs
 

Download problem_in_solve_may_29_2023.mw

Finding too many problems in Version 2023 :(

Update

This seems new problem in V 2023? I just tried it on V 2022 on same PC and no error there. First time used no error.  Here is V 2022 worksheet. So this seems like regression.

Download solve_may_29_2023_V2022.mw

Twice syahirah rahimi asked the same question, and twice it disappeared after I gave him an answer.
It seems this question, already asked on May 19 and 23, has not been moved but deleted, presumably by its author.

In any case, here's my answer.
forward_bbdf_mmcdara.mw
I will delete it in a few hours to give syahirah rahimi time to recover it...eventually.

my program which reads random problems, read one large one. This cause plot to fail with internal error. 

I this known issue?

The expression is too large to post here, so I will only attach worksheet without displaying the actual ff function.

V 2023 on windows 10.

bug_plot_may_29_2023.mw

 hi,

 Does anyone know why my code is not running?

 eqs.mw

My program simply keeps hanging.

It takes me 5 days to complete something which should take 2-3 hrs, since Maple keeps hanging, and I have to keep terminating server.exe and start again. Sometimes when I start again it does not hang where it was. I do this dozens of time per day.

even though I use timelimit on every possible Maple call. The problem also is that when timelimit works, it takes 10-20 times more time than asked. I ask for 10 second timeout, sometimes it timesout after 3-10 minutes if I am lucky.

So I keep trying to make workarounds and I am tired of all of this. Just waste of time. This is getting worst with each new Maple release not better.

Here is an example

restart;
expr:=-1/3*2^(2/3)/((a^2*p+2*a*p^2+p^3+4)/p)^(1/2)*((-1/2*a^2*p-1/2*p^2*a+1/2*p*((a^2*p+2*a*p^2+p^3+4)/p)^(1/2)*a-3)*(-p^2*(-((a^2*p+2*a*p^2+p^3+4)/p)^(1/2)+a+p))^(2/3)+2^(2/3)*(-(a+3/2*p)*p*((a^2*p+2*a*p^2+p^3+4)/p)^(1/2)+a^2*p+5/2*p^2*a+3/2*p^3+3)*p)/(-((a^2*p+2*a*p^2+p^3+4)/p)^(1/2)+a+p)/(-1/2*2^(2/3)*(-p^2*(-((a^2*p+2*a*p^2+p^3+4)/p)^(1/2)+a+p))^(2/3)+p*(p*(-p^2*(-((a^2*p+2*a*p^2+p^3+4)/p)^(1/2)+a+p))^(1/3)+2^(1/3)))/p^2;

try 
    t0:=time[real]();
    timelimit(20,int(expr,p));
catch:
    print("time used ",time[real]()-t0,"seconds");
    print("timed out");
end try;

in Maple 2023, with 128 GB RAM and very fast PC and nothing else is running, it hangs. I could leave it for hrs, the server.exe  is running at full CPU and timelimit is ignored. Timelimit in Maple is useless.

I do not know what else to do. if someone can suggest something, I am willing to try anything before I finally give up.

Hello 

I have implemented FDM for  nonlinear coupled equation 

I that I have to plot U versus Y=i*h and C versus Y 

As well Theta(T) versus Y 

And I want to calculate U(0.5) T(0.5) and C(0.5)

For different values of M 

Like M=1,2,3

Please give me command for the plot and table value of U ,T,&C (0.5)

Download FDM_nonlinear_ode.mw

I do not know if this is known issue. In V 2023  I was calling odetest on solution to ode. It gives the above internal exception.

This happens when there is signum's in the solution and shows up when kernelopts('assertlevel'=2): is set.

Code is below. Could someone verify if they see this or not and if this looks like a new bug? If so, will send email to support.

When I replaced all the signum(...) calls by 1, the exception went away. I do not know now if this happens in V 2022 or not. 

The problem with these internal exception is that they can not be cought. So the whole program crash even when using try/catch.

restart;
interface(warnlevel=4);
kernelopts('assertlevel'=2):
ode:=3*x^2+9*y(x)*x+5*y(x)^2-(6*x^2+4*y(x)*x)*diff(y(x),x) = 0;

current_sol_for_y:=x = -1805/9*(x^2+y(x)*x+1/3*y(x)^2)^2*(7/8*((x+10/7*y(x))*abs(x)+10/21*signum(x)*y(x)^2)*signum(3*x+2*y(x))*signum(21*x^2+30*y(x)*x+10*y(x)^2)+x^2+5/4*y(x)*x+5/12*y(x)^2)^2*(x^2+25/19*y(x)*x+25/57*y(x)^2)^2*c[1]/(11/9*(21/44*abs(x)^3+y(x)*(x+15/22*y(x))*abs(x)+5/33*signum(x)*y(x)^3)*signum(3*x+2*y(x))*signum(21*x^2+30*y(x)*x+10*y(x)^2)+(x^2+5/4*y(x)*x+5/12*y(x)^2)*(x+2/3*y(x)))^2/x^4/(x+2/3*y(x))^2;

odetest(current_sol_for_y,ode)

Download odetest_may_27_2023.mw

Hi,  I went through QuizBuilder (a new feature in Maple 2023) using pre-programmed templates to customize my code. My issue lies in the connection of my random variable F in the 'show solution' to provide the correct limit. Thank you for your insights.

QuizBuilderQprime.mw,

I am not able to make a MWE for this error, as it only shows in the debugger. So it seems Maple internal memory changes or some other library is loaded to cause this. Inside the debugger, I get to a function which does this

DBG> simplify(JacobiDN(x,k)^2*n)

Error, invalid input: simplify/Jacobi/JacobiDN expects its 1st argument, k, to be of type posint, but received 0

Version 2023 on windows 10

In a worksheet, the above works just fine

restart;
simplify(JacobiDN(x,k)^2*n)

Back to the debugger, if I write (2*n) instead of 2*n, then the error goes away

DBG> simplify(JacobiDN(x,k)^(2*n))
JacobiDN(x,k)^(2*n)

The values of x,k,n are all symbols and have no values in the code running:

I have no idea why this happend when I run the code only. It think x is zero in the above for some reason.

Sorry can't make MWE, I wish I can. Something strange happens when I run the code that does not show otherwise. 

Any suggestions how to invetigate this more? Stepping into the simplify code it fails in

DBG> next
`simplify/check_constant`:
   3   return type(r,'And(constant,Or(Not(function),satisfies(f -> evalb(op(f)
         <> NULL))))')

DBG> r
JacobiDN(x,k)^2*n^2

DBG> type(r,'And(constant,Or(Not(function),satisfies(f -> evalb(op(f)          <> NULL))))')
false

DBG> step
`simplify/Jacobi`
`simplify/do`:
  84               userinfo(1,simplify,'applying',new_simp,
                     `function to expression`);

 85               new_r := new_simp(r,symb_mode);  

Here it generate the error.

It has nothing to do with simplify. Here is a call to integrate which gives same error

DBG> lhs(ode)
diff(diff(xi(x),x),x)-k^2*JacobiSN(x,k)*JacobiCN(x,k)/JacobiDN(x,k)*diff(xi(x),x)+(-k^2*JacobiCN(x,k)^2+k^2*JacobiSN(x,k)^2-k^4*JacobiSN(x,k)^2*JacobiCN(x,k)^2/JacobiDN(x,k)^2-JacobiSN(x,k)^2*k^2*n^2+n^2)*xi(x)

DBG> int(lhs(ode),x)
Error, invalid input: simplify/Jacobi/JacobiDN expects its 1st argument, k, to be of type posint, but received 0

DBG> x
x

DBG> k
k

DBG> xi(x)
xi(x)

Hei

Vet noen om Windows 11 støtter Maple 2020? Eller støttes det bare av Windows 10.

If I understand right, the form  is equivalent to  (where the optional index variable is omitted), which produces a sequence of n occurrences of y. But how to explain the following output (of )? 

Download singular_behaviour_of_`seq`.mw

Main code: 

p1 := proc()
    local a := 1, b := 2;
    seq('assign(('a', 'b') = (a + 1, 2*b))', 3);
    print(a, b)
end:

p1():

Any semantic differences for building a set on the fly between

A:="123"; B:="456"; C:="789"; F:="10";
L1:={A,C,B};
L2:={C,F};

And

L:= L1 union L2

vs.

L:= { op(L1) , op(L2) }

They both do the same thing. Is there a reason to prefer one over the other?
 

Download union.mw

Hello,

I want to animate a ball rolling on the surface cos(abs(x)+abs(y)).  The ball mass m is 1kg, radius r is 0.1meters starts at (0.5,0.5,cos(abs(5)+abs(5))) meters using g=9.8. 

If we say the initial velocity of the ball is pushed in some random direction. 

How do I show the path of the ball and animate?

Thanks,

Arthur