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strange result from solve. Internal leak...

nm 8552 Maple 2023
solve
February 17 2024
0 0

Do you think this is a bug? I do not understand solve output. Will send to Maplesoft just in case.

It happens also on Maple 2022. Does it give same result on earlier versions?

2312

> 

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 1672 and is the same as the version installed in this computer, created 2024, February 7, 18:34 hours Pacific Time.`

> 

eq:=1 = exp(-4-c1)/(-exp(-2*c1-8)/LambertW(-exp(-2*c1-8)))^(1/2);
solve(eq,c1)

1 = exp(-4-c1)/(-exp(-2*c1-8)/LambertW(-exp(-2*c1-8)))^(1/2)

-4-(1/2)*ln(_S000003)

> 

PDEtools:-Solve(eq,c1)

c1 = -7/2

Download strange_output_from_solve_feb_17_2024.mw

on solution to ode using Laplace transfo...

nm 8552 Maple 2023
dsolve differential-equations laplace
February 07 2024
1 0

I was trying this ode with Maple

Do you agree this solution is not correct by Maple?

restart;

ode:=diff(y(t),t)+y(t)=Dirac(t);
ic:=y(0)=1;
sol:=dsolve([ode,ic],y(t),method='laplace');

It gives  y(t) = 2*exp(-t)

But from the discussion in the above link we see this is wrong solution. Maple also does not verify it:

odetest(sol,[ode,y(0)=1])

[-Dirac(t), -1]

Would this be considered a bug I should report or not? Note this result is only when using Laplace method. The default method gives better solution.

ode:=diff(y(t),t)+y(t)=Dirac(t);
ic:=y(0)=1;
sol:=dsolve([ode,ic],y(t));
odetest(sol,[ode,y(0)=1])

 

Maple 2023.2.1

How to simplify assuming real domain?...

nm 8552 Maple 2023
simplify simplification
January 20 2024
1 1

Question deleted since it tagged duplicate. Will go search for the duplicate. I did not know there was duplicate one.

update

Here is original question. If moderator thinks it is duplicate feel free to delete. 

I would like to duplicate this simplification done in Mathematica, but in Maple. Mathematica will cancel the exponential term automatically if told the domain is real, but in Maple it willl not.

My attempts in Maple which all fail

restart;


ode := diff(v(x), x, x)*exp(x^2) = 0;
simplify(ode);
simplify(ode) assuming real; #there is no such type
simplify(ode) assuming x::positive;
simplify(ode,symbolic);
use RealDomain in simplify(ode) end use;

How to cancel the exponential term from the above equation in Maple?

is this new bug in integrate? (in Integr...

nm 8552 Maple 2023
integration update int
January 13 2024
2 3

Any one knows if this is a new bug in int()? It happens only when kernelopts('assertlevel'=2): is on.

Using Maple 2023.2.1 on windows 10.

edit: Found another integral. #3 below. The difference now is that this third integral is solved completely when removing Physics update/lib from libname. While the first two are not solved. But all three now do not give exception with the updated libname. New attachment is below.

ps. just in case I also just send bug report to Maplesoft.  

> 

restart;

201864

> 

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 1641. The version installed in this computer is 1637 created 2023, November 29, 17:28 hours Pacific Time, found in the directory C:\Users\Owner\maple\toolbox\2023\Physics Updates\lib\`

> 

kernelopts('assertlevel'=2):
> 

integrand:=(-b*x+a)^(4/3)*(b*x+a)^(8/3);
int(integrand,x,method=_RETURNVERBOSE);

(-b*x+a)^(4/3)*(b*x+a)^(8/3)

Error, (in IntegrationTools:-Indefinite:-ExpandAndMapOverSums) assertion failed, Invalid input for ExpandAndMapOverSums

> 

integrand:=(-b*x+a)^(4/3)*(b*x+a)^(4/3);
int(integrand,x,method=_RETURNVERBOSE)

(-b*x+a)^(4/3)*(b*x+a)^(4/3)

Error, (in IntegrationTools:-Indefinite:-ExpandAndMapOverSums) assertion failed, Invalid input for ExpandAndMapOverSums

> 

integrand:=(-b*x^2+a)^(3/2)*(b*x^2+a)^(3/2);
int(integrand,x,method=_RETURNVERBOSE)

(-b*x^2+a)^(3/2)*(b*x^2+a)^(3/2)

Error, (in IntegrationTools:-Indefinite:-ExpandAndMapOverSums) assertion failed, Invalid input for ExpandAndMapOverSums

> 

libname

"C:\Users\Owner\maple\toolbox\2023\Physics Updates\lib", "C:\Program Files\Maple 2023\lib"

> 

restart;

201864

> 

libname:="C:/Program Files/Maple 2023/lib"

"C:/Program Files/Maple 2023/lib"

> 

kernelopts('assertlevel'=2):
integrand:=(-b*x+a)^(4/3)*(b*x+a)^(8/3);
int(integrand,x,method=_RETURNVERBOSE);

(-b*x+a)^(4/3)*(b*x+a)^(8/3)

["risch" = -(1/1215)*(243*b^4*x^4+324*a*b^3*x^3-450*a^2*b^2*x^2-804*a^3*b*x+47*a^4)*(-b*x+a)^(1/3)*(b*x+a)^(2/3)*((-b*x+a)^2)^(1/3)/(b*((b*x-a)^2)^(1/3))+(int((256/729)*a^5/((b*x-a)^2*(b*x+a))^(1/3), x))*((-b*x+a)^2)^(1/3)*((b*x-a)^2*(b*x+a))^(1/3)/((-b*x+a)^(2/3)*((b*x-a)^2)^(1/3)*(b*x+a)^(1/3)), FAILS = ("gosper", "lookup", "derivativedivides", "default", "norman", "trager", "meijerg", "elliptic", "pseudoelliptic", "parallelrisch", "parts")]

> 

integrand:=(-b*x+a)^(4/3)*(b*x+a)^(4/3);
int(integrand,x,method=_RETURNVERBOSE)

(-b*x+a)^(4/3)*(b*x+a)^(4/3)

["risch" = (3/55)*x*(-5*b^2*x^2+13*a^2)*(-b*x+a)^(1/3)*(b*x+a)^(1/3)*((-b*x+a)^2)^(1/3)/((b*x-a)^2)^(1/3)+(int((16/55)*a^4/((b*x-a)^2*(b*x+a)^2)^(1/3), x))*((-b*x+a)^2)^(1/3)*((b*x-a)^2*(b*x+a)^2)^(1/3)/((-b*x+a)^(2/3)*(b*x+a)^(2/3)*((b*x-a)^2)^(1/3)), FAILS = ("gosper", "lookup", "derivativedivides", "default", "norman", "trager", "meijerg", "elliptic", "pseudoelliptic", "parallelrisch", "parts")]

> 

integrand:=(-b*x^2+a)^(3/2)*(b*x^2+a)^(3/2);
int(integrand,x,method=_RETURNVERBOSE)

(-b*x^2+a)^(3/2)*(b*x^2+a)^(3/2)

["default" = (1/7)*(-b*x^2+a)^(1/2)*(b*x^2+a)^(1/2)*((b/a)^(1/2)*b^4*x^9-4*(b/a)^(1/2)*a^2*b^2*x^5+4*a^4*((-b*x^2+a)/a)^(1/2)*((b*x^2+a)/a)^(1/2)*EllipticF(x*(b/a)^(1/2), I)+3*(b/a)^(1/2)*a^4*x)/((-b^2*x^4+a^2)*(b/a)^(1/2)), "risch" = (1/7)*x*(-b^2*x^4+3*a^2)*(-b*x^2+a)^(1/2)*(b*x^2+a)^(1/2)+(4/7)*a^4*(1-b*x^2/a)^(1/2)*(1+b*x^2/a)^(1/2)*EllipticF(x*(b/a)^(1/2), I)*((-b*x^2+a)*(b*x^2+a))^(1/2)/((b/a)^(1/2)*(-b^2*x^4+a^2)^(1/2)*(-b*x^2+a)^(1/2)*(b*x^2+a)^(1/2)), "elliptic" = (-b*x^2+a)^(1/2)*(b*x^2+a)^(1/2)*(-(1/7)*b^2*x^5*(-b^2*x^4+a^2)^(1/2)+(3/7)*a^2*x*(-b^2*x^4+a^2)^(1/2)+(4/7)*a^4*(1-b*x^2/a)^(1/2)*(1+b*x^2/a)^(1/2)*EllipticF(x*(b/a)^(1/2), I)/((b/a)^(1/2)*(-b^2*x^4+a^2)^(1/2)))/(-b^2*x^4+a^2)^(1/2), FAILS = ("gosper", "lookup", "derivativedivides", "norman", "trager", "meijerg", "pseudoelliptic", "parallelrisch", "parts")]

Download jan_13_2024_integrationTools_expand.mw

Error, (in simplify/RootOf) too many lev...

nm 8552 Maple 2023
ode simplify rootof
January 06 2024
0 3

I've reported this to Maplesoft 6 months ago.

I was wondering if someone with beta version of 2024 could check if these are fixed? (if one is allowed to do so). As these errors keep breaking my program. (not possible to trap).

436

> 

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 1637 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) = (x*y(x)+x^3+x*y(x)^2+y(x)^3)/x^2;
sol:=exp(3*sum(1/(9*_R^2-1)*ln((-_R*x+y(x)-1/3*x)/x),_R = RootOf(27*_Z^3-9*_Z+29)))-c__1*exp(x) = 0;
odetest(sol,ode);

diff(y(x), x) = (x*y(x)+x^3+x*y(x)^2+y(x)^3)/x^2

exp(3*(sum(ln((-_R*x+y(x)-(1/3)*x)/x)/(9*_R^2-1), _R = RootOf(27*_Z^3-9*_Z+29))))-c__1*exp(x) = 0

Error, (in simplify/RootOf) too many levels of recursion

> 

ode:=diff(u(x),x)-1/2*(2*a*u(x)^3+u(x)+2*b)/x = 0;
sol:=2*sum(1/(6*_R^2*a+1)*ln(u(x)-_R),_R = RootOf(2*_Z^3*a+_Z+2*b))-1/2*ln(x)-_C1 = 0;
odetest(sol,ode);

diff(u(x), x)-(1/2)*(2*a*u(x)^3+u(x)+2*b)/x = 0

2*(sum(ln(u(x)-_R)/(6*_R^2*a+1), _R = RootOf(2*_Z^3*a+_Z+2*b)))-(1/2)*ln(x)-_C1 = 0

Error, (in simplify/RootOf) too many levels of recursion

> 

 

Download in_simplify_rootof_too_many_level_of_recursion_jan_6_2024.mw

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