MaplePrimes Questions

In my Maple 2020, I noticed my program got stuck (overnight so let's say for at least 8 hours) on factorization of relatively small integer, so I tried the command standalone:

ifactor(630743190664091077)

and it just froze. For comparsion I tried other SW and programming libraries and basically all of them had the answer instantly. Also looking at the Maple's methods, if I force pollard or lenstra, it also gets the answer instantly. If my understanding is correct, it gets stuck on the method 'morrbril' which is part of the default mix (I tried also mpqs and it gave FAIL, but at least instantly). 

Is that something that still happens by default in newer versions? Seems to me if it gets stuck on 18 decimal digit integer, maybe it's not the best default method...

restart;
with(geometry);
with(plots);
Bl := color = black;
y0 := x -> -ln(1 - exp(-x));
y0 := proc (x) options operator, arrow; -ln(1-exp(-x)) end proc

y1 := x -> -ln(-1 + exp(-x));
y1 := proc (x) options operator, arrow; -ln(-1+exp(-x)) end proc

y2 := x -> -ln(1 + exp(-x));
y2 := proc (x) options operator, arrow; -ln(1+exp(-x)) end proc

p := plot(y0(x), x = 0.02 .. 4, scaling = constrained, color = blue);
p1 := plot(y2(x), x = -4 .. 4, scaling = constrained, color = green);
p2 := plot(y1(x), x = -4 .. 0, scaling = constrained, color = red);
display({p, p1, p2}, view = [-4 .. 4, -4 .. 5]);
Calculate its area; Thank you.

Why Maple can not do this basic combining of two terms? What do  I need to do to help Maple do it? Am I not using the correct command?

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 1795 and is the same as the version installed in this computer, created 2024, August 28, 23:14 hours Pacific Time.`

e:=B^2/(4*(k^n)^(2/3)) - (k^n)^(1/3)*x;

(1/4)*B^2/(k^n)^(2/3)-(k^n)^(1/3)*x

combine(e);

(1/4)*B^2/(k^n)^(2/3)-(k^n)^(1/3)*x

combine(e,symbolic)

(1/4)*B^2*k^(-(2/3)*n)-k^((1/3)*n)*x

combine(e,power)

(1/4)*B^2/(k^n)^(2/3)-(k^n)^(1/3)*x

combine(e,radical)

(1/4)*B^2/(k^n)^(2/3)-(k^n)^(1/3)*x

combine(e,radical,symbolic)

(1/4)*B^2/(k^n)^(2/3)-(k^n)^(1/3)*x

combine(e) assuming positive;

(1/4)*B^2*k^(-(2/3)*n)-k^((1/3)*n)*x

combine(e,abs)

(1/4)*B^2/(k^n)^(2/3)-(k^n)^(1/3)*x

 

 

Download how_to_combine_august_28_2024.mw

For reference, using another software, this is what it gives

Is this valid:

Int(sqrt(x^2+sqrt(x^4+1))/(x+1)/sqrt(x^4+1),x=0..infinity) =
(1/8)*ln((52+36*2^(1/2))*(2+2*2^(1/2))^(1/2)+80*2^(1/2)+113)*(2+2*2^(1/2))^(1/2);

?

SimpleMarsBlyProcedure.mw

Hello Orbital Mechanics and astrodynamics designers of Maple Primes! I am trying to fly to Mars and enter into orbit around it! I know there are a few of you out there that have thought about doing that! Think of all the great mathematicians who have "dabbled" with orbits and astrodynamics! Anyway, here is my problem: I have a simple keplerian model for doing a flyby around Mars and I have a simple model for Reaction Control Thrusters (RCS) to help put the spacecraft into orbit around Mars.  The first thruster burn happens as the spacecraft enters Mars' Sphere Of Influence (SOI) when it is less than 577000 km away and that burn is needed.  I do that with a piecewise continous function with the conditions set up to fire the thrusters.  But in that same piecewise continous function, I have a 2nd thruster firing with the times called out to fire again.  But this time I want to fire the thruster at periapse (P) in order to go into orbit around Mars.  I believe that the Rosenbrock and/or RKF45 are not responding to the 2nd conditions in the piecewise function I have set up for the thruster firing times.  I have to fire the thruster at periapse and I know that time I reach the periapse point.  Also, in my Maple file you will see that I can "cant" the spacecraft to better control the direction of my burns.  

The problem I am encountering seems to be more about the piecewise functions with multiple conditions and expressions.  Please take a look at my Maple file and see if any of you Orbital Mechanics and/or astrodynamicsts familar with Maple can see what I am doing wrong here.  You don't have to be a astrodyamicist per se, just perhaps you have run across this problem of piecewise functions in dsolve with method = rosenbrock or RKF45. 

Thank you. 

In this post about a non-linear system of equations solutions were sougth. It turned out that there were no non-trivial solutions for the given numerical values. However, with different numerical values there should be solutions.

In analogy to the fundamental theorem of algebra (which clearly states the number of roots),
I wonder if Maple provides commands that can estimate an upper bound of roots/solutions for a system of multivariate equations by analysing the structure of the system of equations rather than attempting to solve it.

I am not sure if rules, methods or theorems exist at all for multivariate problems. Maybe it is a stupid question but for me this was non-trivial for the case given above.

In the Standard interface, the length of an expression that display in the worksheet can be limited using the Options dialog: Options Dialog - Precision Tab - Maple Help. However, I would like to know if I can change this option programmatically. The closest interface variables are elisiontermsbefore, elisiontermsafter and termelisionthreshold, but as the aforementioned help page states, they control the “term elision” and are not the same as “expression length limit”. So, is this possible? 

Writng the Pde wave function solution in a textbook form ?
golfvergelijking_oplossing_gebruiken_om_integraaluisom_te_halen_voorbeeld.mw

Below is the code in Maple 2022, and then I describe the problem.
restart;
with(plots);
a := 0.5;
j := BesselJ(0, sqrt(2*I)*sqrt(x^2 + y^2)*a)/BesselJ(0, sqrt(2*I)*a);
A := sqrt(Re(j)^2 + Im(j)^2);
densityplot(A, x = -1 .. 1, y = -sqrt(-x^2 + 1) .. sqrt(-x^2 + 1), grid = [68, 68], style = patchnogrid, scaletorange = 0 .. 1);

 

Thus, I have a real function of two variables: $A(x, y)$. At zero it is minimal (value 0.996). At the boundary of the unit circle it is maximal with a value equal to 1. In theory, scaletorange = 0 .. 1 should give a picture with almost perfectly white everywhere in the circle since the function values ​​are very close to 1. However, both with scaletorange and without it, the command produces a picture with a significantly dark circle in the center...

I am looking for something similar to color functions of plot3D. plot.options is directing me to plot,color where I cannot find an example. I tried

plot(floor(x),x=-3..3,color=floor(x))

Error, (in plot) invalid color specification: floor(x)

Suppose I have a list of differential equations:

L:=[x*diff(f(x),x)+2*x+1=0, 4*(diff(f(x),x$2))^2+7*diff(f(x),x)-2=0, x*diff(f(x),x)+2*x+1=0, 3*(diff(f(x),x))^2-f(x)-1=0];

how can I rewrite this list such that 
L:=[[x*diff(f(x),x)+2*x+1=0,2], [4*(diff(f(x),x$2))^2+7*diff(f(x),x)-2=0,1], [3*(diff(f(x),x))^2-f(x)-1=0,1]];
i.e., rewrite this list as the [equation, Number of occurrences in the list]

Hi all guys, it is simple equation, I wanna get the expression of w=()^(1/4) which consists zg & fg. I use solve command but fails, could you please help me?

NULL

p := (1/24)*z*g[u]+(1/24)*f*g[z]-(1/144000)*w^4*(f*g[z]+z*g[u])

(1/24)*z*g[u]+(1/24)*f*g[z]-(1/144000)*w^4*(f*g[z]+z*g[u])

(1)

solve(p = 0, w)

2*375^(1/4), (2*I)*375^(1/4), -2*375^(1/4), -(2*I)*375^(1/4)

(2)

NULL

Download solve_an_equation.mw

Dear all, why "has" always returns false ?

I do not know if this is how it always been in Maple. But now I noticed when I set assertlevel to 2, in order to catch wrong assignment type in my code, the try/catch do not catch such an error.  

My question is: Has it always been like this in Maple? May be it was, I am just asking for confirmation. I seem to remember I was able to trap such error before.

Here is MWE

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;

interface(warnlevel=4):
kernelopts('assertlevel'=2):

 

foo:=proc();
local C_sol::list;
   try
      C_sol := 1;
   catch:
      print("error detected in my code");
   end try;
end proc:

foo(); #unable to catch assignment error

Error, (in foo) assertion failed in assignment to C_sol, expected list, got 1

 

 

Download why_trap_do_not_catch_assignment_error.mw

I'm struggling getting read statements to work in code attachments.

Are there any limitations for the read command?

Test.zip

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