Maple 2023 Questions and Posts

These are Posts and Questions associated with the product, Maple 2023

I bought Maple 2023 student version. (I am student) and installed it on windows 10.

I wanted to try it on Linux to see if runs better. So Installed the Linux version. When I tried to activate using the same purchase code I got, I get error that I have no more activations or I exceeded the number of activations.

But I installed Maple 2023 only one time, on windows which is my main OS. Never installed it anywhere else before.

Is one really only allowed one installation?

How would then I can try Maple on Linux but keep my Maple on windows until I decide if Maple works better on Linux or not?

Hello everyone,

Please, I need your help. I want to plot the spectrum of a dataset in #Problem 1.

In #Problem 2 If it is possible, how can I convert that function from the time domain to the frequency domain?

Thank you

Fourier_transform.mw

I think the GF function, input, accepts out-of-range inputs.

From ?GF: The G:-input and G:-output commands convert from an integer in the range 
  "0 .. p^k - 1" to the corresponding polynomial and back

GF_strange.mw

The first GF was from a typo. I think it should have produced an error message, according to help.
If I understand correctly, GF(7,1) should only have 7 members.
The second GF is to allow the input 28856.

Tom Dean

This first order ode is quadrature with initial conditions. By existence theorem it has solution and is unique on some interval that includes the initial conditions (because f and f_y  are continuous on the initial condition).

But for some reason Maple can't find the solution, unless one adds 'implicit' option. Why is that? I thought that Maple will automatically return implicit solution if can't find explicit solution. 

So does one then needs to try with implicit solution again if no solution is returned? I am basically asking if this is expected behavior of dsolve.

Below is worksheet also with the solution that Maple verifies is valid and satisfies the ode and also initial conditions.

ode:=diff(y(x), x) = sin(y(x)) + 1;
ic:=y(0)=Pi;
sol:=dsolve([ode,ic]);

20212

interface(version);

`Standard Worksheet Interface, Maple 2023.2, Windows 10, November 24 2023 Build ID 1762575`

Physics:-Version();

`The "Physics Updates" version in the MapleCloud is 1618 and is the same as the version installed in this computer, created 2023, November 29, 17:28 hours Pacific Time.`

restart;

28544

ode:=diff(y(x), x) = sin(y(x)) + 1;
ic:=y(0)=Pi;
sol:=dsolve([ode,ic]);

diff(y(x), x) = sin(y(x))+1

y(0) = Pi

maple_sol:=dsolve([ode,ic],'implicit');
odetest(maple_sol,[ode,ic])

(2+x*tan((1/2)*y(x))+x)/(tan((1/2)*y(x))+1) = 0

[0, 0]

maple_sol:=dsolve([ode,ic],y(x),'explicit');

mysol:=y(x)=2*arccos(-x/(sqrt(4+4*x+2*x^2)));
odetest(mysol,[ode,ic]) assuming x>=0

y(x) = 2*Pi-2*arccos(x/(2*x^2+4*x+4)^(1/2))

[0, 0]

 


 

Download unable_to_dsolve_quadature_dec_22_2023.mw

 

Why does

restart;
eq:=Z^2=y/x;
solve(eq,Z)

give

I never told maple that y>=0 and x>=0 ?   I was expecting what we will do by hand. which is

Note that sqrt(x*y) is same as sqrt(x)*sqrt(y) only when y and x are not negative. 

Is there an option to make Maple not do this and give same result as above? I tried PDEtools:-Solve and it gives same solution as solve.

Maple 2023.2.1 on windows 10

This worksheet loses contact with the kernel. I asked Tech Support. How do I report a bug?

Hung.mw

The last line was a typo, but, it should not lose contact with the kernel...

After executing the print statement,

> 1

produces the error message.

Tom Dean

For example, here are two equations containing trigonometric functions (Note that they do not form one system!): 

restart; # There are more examples, yet for the sake of briefness, they are omitted here. 
eqn__0 := cos(x)*cos(y)*cos(x + y) = 2*(sin(x)*sin(y) - 1)*2*(sin(x)*sin(x + y) - 1)*2*(sin(y)*sin(x + y) - 1):
eqn__1 := (cos(x + y) - (cos(x) + cos(y)) + 1)**2 + 2*cos(x)*cos(y)*cos(x + y) = 0:

Unfortunately, none of 

(* Tag0 *) RealDomain:-solve(eqn__0, {y, x}):
(* Tag1 *) solve(eqn__0, {y, x}) assuming y + x >= 0, (y, x) <=~ Pi:
(* Tag2 *) RealDomain:-solve(eqn__1, {y, x}):
(* Tag3 *) solve(eqn__1, {y, x}) assuming y + x >= 0, (y, x) <=~ Pi:

outputs concise solutions.
Using `plot3d`, it is easy to check that when "And(y + x >= 0, (y, x) <=~ Pi)", “{y = Pi/2, x = 0}, {y = Pi/3, x = Pi/3}, {y = 0, x = Pi/2}, {y = Pi/2, x = Pi/2}” is both the only solution to "eqn__0" and the only solution to "eqn__1". But how to get Maple to do so without manual intervention?

Edit. The main purpose is to automatically find the generic solutions to each of the two equations (Tag0 and Tag2) (separately). Now that the cosine and sine functions are both periodic with period 2π and both (lhs - rhs)(eqn__0) and (lhs - rhs)(eqn__1) are even symmetric, it is enough to focus only on the region y + x ≥ 0 ∧ (y, x) ≤~ Pi. So, in theory, a second-best workaround should be Tag1 and Tag3. However, why is Maple still unable to find the four exact solutions above?

This could be new bug in 2023.2.1, could someone else confirm if it is in earlier versions 2023.2 ?

restart;
ode:=diff(y(x),x)-y(x)^2-m*y(x)*cot(x)-b^2*sin(x)^(2*m) = 0;
DEtools:-symgen(ode)

Error, (in trig/reduce) too many levels of recursion

After about 30 seconds.

I tried it in Maple 2022.2  I waited for more than 10 minutes and it was still running.  If you think it is new bug, will send email to Maple support.

The big problem with these Maple internal errors, is that it is not possible to trap them with try/catch. So the program simply crashes and there is no workaround.

``

restart;

35880

interface(version)

`Standard Worksheet Interface, Maple 2023.2, Windows 10, November 24 2023 Build ID 1762575`

Physics:-Version()

`The "Physics Updates" version in the MapleCloud is 1615 and is the same as the version installed in this computer, created 2023, November 29, 17:28 hours Pacific Time.`

ode:=diff(y(x),x)-y(x)^2-m*y(x)*cot(x)-b^2*sin(x)^(2*m) = 0;

diff(y(x), x)-y(x)^2-m*y(x)*cot(x)-b^2*sin(x)^(2*m) = 0

DEtools:-symgen(ode);

Error, (in tools/map) too many levels of recursion

 


reported to Maple support

Download trig_reduce_recursion_dec_20_2023.mw

 I have been trying to run a code to plot a region of stability for a numerical method for solving IVPs. Apart from the fact that it is taking time to run, it is giving me errors: 'Error; (inplots/ implicitplot/factor) and  Error; (inplot/ iplot2d:-Levels ) could not evaluate expression' 

 Attached here is the code:

K=4

NULL

with(LinearAlgebra):

NULL

P1 := simplify(A1-ScalarMultiply(A3, z)-ScalarMultiply(A5, z^3)):

Error, (in plots/implicitplot/factor) invalid input: the following extra unknowns were found in the input expression: {P5[4]}

Error, (in plot/iplot2d:-Levels) could not evaluate expression

NULL

Download RAS(TDFFAM).mw

The help page mentions: 

The package supports five q-hypergeometric terms. They are q-Pochhammer symbol, q-binomial coefficient, q-brackets, q-factorial, and q-Gamma, which correspond to the five functions , , , , and . 

But what about the so-called q-hypergeometric function? Though there exist QDifferenceEquations:-IsQHypergeometricTerm and QDifferenceEquations:-QHypergeometricSolution in Maple, they do not seem to represent the function itself
For example, how to type the q-Gauss sum (cf. DLMF's §17.6(i)) or verify the last “simple series expression” given in Basic hypergeometric series - Wikipedia? In Mma, one may achieve these with something like 

while 

convert("QHypergeometricPFQ[{a, b}, {c}, q, c/(a b)]", 'FromMma', 'evaluate');
 = 
                              /                 c \
            QHypergeometricPFQ|[a, b], [c], q, ---|
                              \                a b/

So has the q-hypergeometric function been implemented in Maple?

What is the correct way, in code, to check if Maple result contains any one of its own global build in symbols such as _Z or _C or any such symbol it uses?

I need to bypass this result. Currently I check explicitly, but I am sure there is a better way. Here is an example

r:=discont(1/tan(x),x);

This returns 

Currently I do 

if has(r,_Z1)  or has(r,_Z2) or has(r,_Z3) then
etc...

same for _C1, _C2., etc...

But this method is not robust. The problem is that _Z1 is symbol. So I can't check for symbol type in the  result as result could possibly have one of my own symbols there depending on input.

Is there  better way to do this? I am only asking about output of discont here and not any other Maple function. I assume discont uses _Zn only but I am not sure. It could use different symbol? 

given 

r1:=   -1 <= x and x <= 0;
r2:=   0 <= x and x <= 1;

We see that the above can be simplified to one inequality

-1<= x and x<=1

The closest I found to do this is

r1:=-1 <= x and x <= 0;
r2:=0 <= x and x <= 1;
solve(r1 or r2,x);

which gives RealRange(-1, 1) but I'd like to get the form  -1<= x and x<=1 similar to:

I tried convert to piecewise and simplify and few other things. Is there a trick in Maple to simplify/combine/join inequalites like the above? i.e. convert RealRange(-1, 1) to -1<=x and x<=1 

everything is on the real line.

Maple 2023.2

> kernelopts(version)
   Maple 2023.2, X86 64 LINUX, Nov 24 2023, Build ID 1762575

I got results I did not expect using &^ and mod. So, I created a simple example.

powermod.mw

&^ ... mod does not seem to allow () to set order of execution where ^ ... mod does.

How does &^ ... mod arrive at the values that are different than ^ ... mod?

Tom Dean

how do i change the decimal separator, i cant find the setting anywhere. I already changed all the settings in windows related to this. It displays numbers the way i want it to, by separating decimals using a comma, since that's what I'm used to. My regional settings on windows are also correct, however I can't seem to get maple to use the same separation. It looks like 123.13 when i want it to be 123,13. I couldn't find a solution online so I made an account here in the hope of finding a solution. Thanks

I would like to simulate the evolution of the so-called B, C, K, W system and SKI combinator calculus in Maple.
The rewrite rules of them are simple: 

S(x)(y)(z)=x(z)(y(z))
K(x)(y)=x, and 
I(x)=x. (Note that since  is protected, I shall use  hereafter.)

However, if I try to evaluate the following example given in the  article, 

Maple will only return an unchanged result: 

restart;
applyrule([cS(x::anything)(y::anything)(z::anything) = x(z)(y(z)), 
   cK(x::anything)(y::anything) = x, cI(x::anything) = x], 
  cS(cK(cS(cI)))(cS(cK(cK))(cI))(x)(y)); # Unable to reduce??? 
 = 
              cS(cK(cS(cI)))(cS(cK(cK))(cI))(x)(y)

I believe that this is not an outlier.
Here are two additional instances: 

> rls := [cS(x::anything)(y::anything)(z::anything) = x(z)(y(z)), cK(x::anything)(y::anything) = x]:
> map2(applyrule, rls, [cS(cS(cS)(cS))(cS)(cS(cS))(cK), cS(cS(cS))(cS)(cS)(cS)(cS(cS)(cK(cK)))]);
                       [cS(cS(cS)(cS))(cS)(cS(cS))(cK), cS(cS(cS))(cS)(cS)(cS)(cS(cS)(cK(cK)))]

>

So why can't `applyrule` apply rules as desired? Meanwhile, how to automatically and thoroughly (like :-eval['recurse'] or MmaTranslator:-Mma:-ReplaceRepeated) apply those transformation rules to 

  1. , and

I have read something like How to apply a recursive rule in an expression? - MaplePrimes, but they are not the same issue.

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