Unanswered Questions

String and parse on decimal number...

Asked by: nm 11353

February 08 2025

1 1

Do you think the result of String(0.016) should be "0.016" instead of ".16e-1" ?

Any reason why it gives the second form and not the first? Now have to keep using sprintf to force formating as decimal point. Is this documented somewhere? quick search did not find anything do far.

Maple 2024.2 on windows.

>	s:="0.016";

>	z:= :-parse(s);

>	String(z);

>	sprintf("%0.3f",z);

Download string_of_decimal_number.mw

How can I find how Statistics:-Mean is coded?...

Asked by: mmcdara 7891

February 08 2025

2 4

I'd like to know the details of the method Statistics:-Mean uses to numerically estimate the expectation of a random variable.

showstat seems of no use and neither seems to be LibraryTools[Browse]();

Here are two examples: the first one (1D) suggests Statistics:-Mean could use some evalf/Int method, but the conclusion to draw from the second example (R²--> R) is less clear.

How_does_Mean_proceed.mw

Thanks in advance

PS: I already asked a similar question months ago but didn't get any reply.
Even answers such as “We don't know” or “We don't care” would suit me better than their absence.

How to get a graph of this problem...

Asked by: Saha 80

February 04 2025

0 1

scmch.mw

I can't get a graph. Is this code is correct.Please help.

How to integrate it?...

Asked by: Ahmed111 135

February 03 2025

0 2

How to integrate eq (4)? Since 'a', 'b', and 'c' are constant.

Download integration.mw

How to get solution Soll11 for the reduced Liouvil...

Asked by: janhardo 700

February 02 2025

0 5

The modified Liouville equation

>

How to solve this pde for a general solution ?

The general solution in this form exist.

>

restart;

>

with(PDEtools): declare(u(x,t)); U:=diff_table(u(x,t));
PDE1:=U[t,t]=a^2*U[x,x]+b*exp(beta*U[]);
Sol11:=u(x,t)=1/beta*ln(2*(B^2-a^2*A^2)/(b*beta*(A*x+B*t+C)^2));
Sol12:=S->u(x,t)=1/beta*ln(8*a^2*C/(b*beta))
-2/beta*ln(S*(x+A)^2-S*a^2*(t+B)^2+S*C);
Test11:=pdetest(Sol11,PDE1);
Test12:=pdetest(Sol12(1),PDE1);
Test13:=pdetest(Sol12(-1),PDE1);

u(x, t) = ln(2*(-A^2*a^2+B^2)/(b*beta*(A*x+B*t+C)^2))/beta

proc (S) options operator, arrow; u(x, t) = ln(8*a^2*C/(b*beta))/beta-2*ln(S*(x+A)^2-S*a^2*(t+B)^2+S*C)/beta end proc

(1)

The Soll11 can be plotted with a Explore plot in this form of soll11 with th eparameters , but suppose i try to get the general solution in Maple ?

>

>	ans := pdsolve(PDE1);

What solvin gstrategy to follow ? : the pde is a non-linear wave eqation with a exponentiel sourceterm
It seems that the pde can reduced to a ode? :

>

with(PDEtools):
declare(u(x,t));

# Stap 1: Definieer de PDE
PDE := diff(u(x,t), t,t) = a^2 * diff(u(x,t), x,x) + b * exp(beta * u(x,t));

# Stap 2: Definieer de transformatie naar karakteristieke variabelen
# Nieuw: x en t uitgedrukt in ξ en η
tr := {
    x = (xi + eta)/2,
    t = (eta - xi)/(2*a)
};

# Pas de transformatie toe op de PDE
simplified_PDE := dchange(tr, PDE, [xi, eta], params = [a, b, beta], simplify);

# Stap 3: Definieer de algemene oplossing
solution := u(x,t) = (1/beta) * ln(
    (-8*a^2/(b*beta)) *
    diff(_F1(x - a*t), x) * diff(_F2(x + a*t), x) /
    (_F1(x - a*t) + _F2(x + a*t))^2
);

# Stap 4: Controleer de oplossing (optioneel)
pdetest(solution, PDE); # Moet 0 teruggeven als correct

u(x, t) = ln(-8*a^2*(D(_F1))(-a*t+x)*(D(_F2))(a*t+x)/(b*beta*(_F1(-a*t+x)+_F2(a*t+x))^2))/beta

(2)

missing some steps here : solution u without the pde reduced ?
there is a ode ?

>	# Definieer de ODE # vorige stappen ontbreken van de reduktie ode := (v^2 - a^2) * diff(f(xi), xi, xi) = b * exp(beta * f(xi)); # Algemene oplossing zoeken sol := dsolve(ode, f(xi));

f(xi) = ln((1/2)*c__1*(tan((1/2)*(-c__1*a^2*beta+c__1*beta*v^2)^(1/2)*(c__2+xi)/(a^2-v^2))^2+1)/b)/beta

(3)

>

, ,

Question : how do i arrive on Soll11 in Maple ?

Download liouville_reduced_2-2-2025_mprimes_vraag.mw

Is it possible?...

Asked by: Ali Guzel 80

February 01 2025

2 19

Hi All,

Maple is changing fast. It is not possible to run some older codes.

Is it possible those who have a valid Maple license to have the old versions free of charge?

I have Maple 7, 2018, 2021 licenses but still have problem running older codes.

How to simplify Eqs. (3), (5) and (6) and write in...

Asked by: FZ 30

January 31 2025

0 5

>

restart; with(PDEtools); declare(F(x, t), G(x, t), H(x, t))

(1)

>

q := 1-(diff(diff(log(F(x, t)), x), t)); r := G/F; s := H/F

1-(diff(diff(F(x, t), t), x))/F(x, t)+(diff(F(x, t), x))*(diff(F(x, t), t))/F(x, t)^2

(2)

>

r1s1 := r*s; r1s1der := diff(r1s1(x, t), x)

>

(3)

>

D_x_x_G_F := (diff(G(x, t), x, x))*F(x, t)-2*(diff(G(x, t), x))*(diff(F(x, t), x))+G(x, t)*(diff(F(x, t), x, x)); D_t_t_F_F := F(x, t)*(diff(F(x, t), `$`(t, 2)))-2*(diff(F(x, t), t))^2

(4)

>

((-F*F(x, t)*G(x, t)+2*G*F(x, t)^2)*(diff(diff(F(x, t), t), x))+(diff(diff(G(x, t), t), x))*F*F(x, t)^2+((2*F*G(x, t)-2*G*F(x, t))*(diff(F(x, t), x))-F*(diff(G(x, t), x))*F(x, t))*(diff(F(x, t), t))-(diff(G(x, t), t))*(diff(F(x, t), x))*F*F(x, t)-2*G*F(x, t)^3)/(F*F(x, t)^3) = 0

(5)

>

((-F*F(x, t)*H(x, t)+2*H*F(x, t)^2)*(diff(diff(F(x, t), t), x))+(diff(diff(H(x, t), t), x))*F*F(x, t)^2+((2*F*H(x, t)-2*H*F(x, t))*(diff(F(x, t), x))-F*(diff(H(x, t), x))*F(x, t))*(diff(F(x, t), t))-(diff(H(x, t), t))*(diff(F(x, t), x))*F*F(x, t)-2*H*F(x, t)^3)/(F*F(x, t)^3) = 0

(6)

>

Download BE.mw

Maple Software Not Opening...

Asked by: reygarcia 0

January 30 2025

0 2

Hi,

Experiencing the following problem. One of our servers was cloned, the GUID was replaced and then rejoined to the domain. All applications are working exept Maple. The application launches but then closes right away. No error messages provided so not sure where else to look for possible fixes to this problem. The application is runing on Server 2022.

Thank you.

How find true parameter which satisfy pde?...

Asked by: salim-barzani 1560

January 28 2025

0 2

>

(1)

>

(2)

>

(3)

>

(4)

>

(5)

>

LL := diff(diff(diff(diff(diff(f(x, y, z, t), x), x), x), x), x)-(diff(diff(diff(f(x, y, z, t), x), x), x))-(diff(diff(diff(f(x, y, z, t), t), t), x))-(diff(diff(diff(f(x, y, z, t), t), x), x))-2*(diff(diff(diff(f(x, y, z, t), t), x), y))-(diff(diff(diff(f(x, y, z, t), x), x), y))-(diff(diff(diff(f(x, y, z, t), x), x), z))-(diff(diff(diff(f(x, y, z, t), x), y), y)) = 0

(6)

>

S22 := f(x, y, z, t) = 1+exp((-(1/2)*k[1]-l[1]+(1/2)*sqrt(4*k[1]^4-3*k[1]^2-4*k[1]*s[1]))*t+k[1]*x+l[1]*y+s[1]*z)+exp(k[2]*x+l[2]*y+s[2]*z+(-(1/2)*k[2]-l[2]+(1/2)*sqrt(4*k[2]^4-3*k[2]^2-4*k[2]*s[2]))*t)+B[1]*exp((-(1/2)*k[1]-l[1]+(1/2)*sqrt(4*k[1]^4-3*k[1]^2-4*k[1]*s[1]))*t+k[1]*x+l[1]*y+s[1]*z+k[2]*x+l[2]*y+s[2]*z+(-(1/2)*k[2]-l[2]+(1/2)*sqrt(4*k[2]^4-3*k[2]^2-4*k[2]*s[2]))*t)

f(x, y, z, t) = 1+exp((-(1/2)*k[1]-l[1]+(1/2)*(4*k[1]^4-3*k[1]^2-4*k[1]*s[1])^(1/2))*t+k[1]*x+l[1]*y+s[1]*z)+exp(k[2]*x+l[2]*y+s[2]*z+(-(1/2)*k[2]-l[2]+(1/2)*(4*k[2]^4-3*k[2]^2-4*k[2]*s[2])^(1/2))*t)+B[1]*exp((-(1/2)*k[1]-l[1]+(1/2)*(4*k[1]^4-3*k[1]^2-4*k[1]*s[1])^(1/2))*t+k[1]*x+l[1]*y+s[1]*z+k[2]*x+l[2]*y+s[2]*z+(-(1/2)*k[2]-l[2]+(1/2)*(4*k[2]^4-3*k[2]^2-4*k[2]*s[2])^(1/2))*t)

(7)

>

(8)

>

(9)

>

${t, x, y, z, B[1], k[1], k[2], l[1], l[2], s[1], s[2], (4*k[1]^4-3*k[1]^2-4*k[1]*s[1])^(1/2), (4*k[2]^4-3*k[2]^2-4*k[2]*s[2])^(1/2), exp(k[2]*x+l[2]*y+s[2]*z+(-(1/2)*k[2]-l[2]+(1/2)*(4*k[2]^4-3*k[2]^2-4*k[2]*s[2])^(1/2))*t), exp((-(1/2)*k[1]-l[1]+(1/2)*(4*k[1]^4-3*k[1]^2-4*k[1]*s[1])^(1/2))*t+k[1]*x+l[1]*y+s[1]*z), exp((-(1/2)*k[1]-l[1]+(1/2)*(4*k[1]^4-3*k[1]^2-4*k[1]*s[1])^(1/2))*t+k[1]*x+l[1]*y+s[1]*z+k[2]*x+l[2]*y+s[2]*z+(-(1/2)*k[2]-l[2]+(1/2)*(4*k[2]^4-3*k[2]^2-4*k[2]*s[2])^(1/2))*t)}$

(10)

>

eq2 := algsubs(exp((-(1/2)*k[1]-l[1]+(1/2)*sqrt(4*k[1]^4-3*k[1]^2-4*k[1]*s[1]))*t+k[1]*x+l[1]*y+s[1]*z) = X, L4)

(11)

>

-(1/2)*(k[1]+k[2])*B[1]*((k[1]*(4*k[1]^3-3*k[1]-4*s[1]))^(1/2)*(k[2]*(4*k[2]^3-3*k[2]-4*s[2]))^(1/2)-8*k[1]*k[2]^3-12*k[2]^2*k[1]^2+(-8*k[1]^3+3*k[1]+2*s[1])*k[2]+2*s[2]*k[1])*exp((1/2)*t*(k[1]*(4*k[1]^3-3*k[1]-4*s[1]))^(1/2)+(1/2)*t*(k[2]*(4*k[2]^3-3*k[2]-4*s[2]))^(1/2)+(1/2)*(-k[1]-k[2]-2*l[1]-2*l[2])*t+k[1]*x+k[2]*x+l[1]*y+l[2]*y+z*(s[1]+s[2])) = 0

(12)

>

${t, x, y, z, B[1], k[1], k[2], l[1], l[2], s[1], s[2], (k[1]*(4*k[1]^3-3*k[1]-4*s[1]))^(1/2), (k[2]*(4*k[2]^3-3*k[2]-4*s[2]))^(1/2), exp((1/2)*t*(k[1]*(4*k[1]^3-3*k[1]-4*s[1]))^(1/2)+(1/2)*t*(k[2]*(4*k[2]^3-3*k[2]-4*s[2]))^(1/2)+(1/2)*(-k[1]-k[2]-2*l[1]-2*l[2])*t+k[1]*x+k[2]*x+l[1]*y+l[2]*y+z*(s[1]+s[2]))}$

(13)

>

eq4 := algsubs(exp((1/2)*t*sqrt(k[1]*(4*k[1]^3-3*k[1]-4*s[1]))+(1/2)*t*sqrt(k[2]*(4*k[2]^3-3*k[2]-4*s[2]))+(1/2)*(-k[1]-k[2]-2*l[1]-2*l[2])*t+k[1]*x+k[2]*x+l[1]*y+l[2]*y+z*(s[1]+s[2])) = V, eq3)

-(1/2)*(k[1]+k[2])*B[1]*(-8*k[2]*k[1]^3-12*k[2]^2*k[1]^2-8*k[1]*k[2]^3+(k[1]*(4*k[1]^3-3*k[1]-4*s[1]))^(1/2)*(k[2]*(4*k[2]^3-3*k[2]-4*s[2]))^(1/2)+3*k[1]*k[2]+2*s[2]*k[1]+2*s[1]*k[2])*V = 0

(14)

>

${V, B[1], k[1], k[2], s[1], s[2], (k[1]*(4*k[1]^3-3*k[1]-4*s[1]))^(1/2), (k[2]*(4*k[2]^3-3*k[2]-4*s[2]))^(1/2)}$

(15)

>

eqs := {coeffs(collect(numer(normal(lhs(eq4))), {V}, 'distributed'), {V})}; nops(%); indets(eqs)

${-(k[1]+k[2])*B[1]*(-8*k[2]*k[1]^3-12*k[2]^2*k[1]^2-8*k[1]*k[2]^3+(k[1]*(4*k[1]^3-3*k[1]-4*s[1]))^(1/2)*(k[2]*(4*k[2]^3-3*k[2]-4*s[2]))^(1/2)+3*k[1]*k[2]+2*s[2]*k[1]+2*s[1]*k[2])}$

${B[1], k[1], k[2], s[1], s[2], (k[1]*(4*k[1]^3-3*k[1]-4*s[1]))^(1/2), (k[2]*(4*k[2]^3-3*k[2]-4*s[2]))^(1/2)}$

(16)

>

${B[1], k[1], k[2], s[1], s[2], (k[1]*(4*k[1]^3-3*k[1]-4*s[1]))^(1/2), (k[2]*(4*k[2]^3-3*k[2]-4*s[2]))^(1/2)}$

Warning, solving for expressions other than names or functions is not recommended.

${B[1] = B[1], k[1] = -k[2], k[2] = k[2], s[1] = s[1], s[2] = s[2], (k[1]*(4*k[1]^3-3*k[1]-4*s[1]))^(1/2) = (k[1]*(4*k[1]^3-3*k[1]-4*s[1]))^(1/2), (k[2]*(4*k[2]^3-3*k[2]-4*s[2]))^(1/2) = (k[2]*(4*k[2]^3-3*k[2]-4*s[2]))^(1/2)}, {B[1] = 0, k[1] = k[1], k[2] = k[2], s[1] = s[1], s[2] = s[2], (k[1]*(4*k[1]^3-3*k[1]-4*s[1]))^(1/2) = (k[1]*(4*k[1]^3-3*k[1]-4*s[1]))^(1/2), (k[2]*(4*k[2]^3-3*k[2]-4*s[2]))^(1/2) = (k[2]*(4*k[2]^3-3*k[2]-4*s[2]))^(1/2)}, {B[1] = B[1], k[1] = k[1], k[2] = k[2], s[1] = (1/2)*(8*k[2]*k[1]^3+12*k[2]^2*k[1]^2+8*k[1]*k[2]^3-3*k[1]*k[2]-2*s[2]*k[1]-(k[1]*(4*k[1]^3-3*k[1]-4*s[1]))^(1/2)*(k[2]*(4*k[2]^3-3*k[2]-4*s[2]))^(1/2))/k[2], s[2] = s[2], (k[1]*(4*k[1]^3-3*k[1]-4*s[1]))^(1/2) = (k[1]*(4*k[1]^3-3*k[1]-4*s[1]))^(1/2), (k[2]*(4*k[2]^3-3*k[2]-4*s[2]))^(1/2) = (k[2]*(4*k[2]^3-3*k[2]-4*s[2]))^(1/2)}$

(17)

>

${B[1] = B[1], k[1] = -k[2], k[2] = k[2], s[1] = s[1], s[2] = s[2], (k[1]*(4*k[1]^3-3*k[1]-4*s[1]))^(1/2) = (k[1]*(4*k[1]^3-3*k[1]-4*s[1]))^(1/2), (k[2]*(4*k[2]^3-3*k[2]-4*s[2]))^(1/2) = (k[2]*(4*k[2]^3-3*k[2]-4*s[2]))^(1/2)}$

(18)

>

(19)

Download hard_parameters.mw

How can fix `[Length of output exceeds limit of 10...

Asked by: salim-barzani 1560

January 26 2025

1 4

in a lot of my equation i have such problem and really i don't know how fix this also i try to put : in end and sometime is work and i keep contionues but sometime not there is any way for solve this problem?

limit.mw

Is there some way to avoid this behaviour?...

Asked by: mmcdara 7891

January 25 2025

0 2

Let us suppose I open Maple, write a worksheet, save it in a folder A and then quit Maple.

Now I run a new session by double clicking on some mw file located in folder B, let us say //B/test_1.mw.
Once opened I do some modifications and decide to save this worksheet into a new file, let us say test_2.mw in the same folder B test_1.mw belongs to (which means I use Save As from the menu bar)

I'm regularly fooled by the fact that the default folder is not B, but the folder A I used in the previous session.

I find this very unpleasant.
Is this a Maple (2015) issue or something related to my operating system (Mac OSX Catalina)?
In case it is a Maple issue which is still present in more recent Maple versions, Would it be possible to set the default backup folder to be the folder to which the active worksheet belongs?

Thanks in advance

Customized Key Bindings?...

Asked by: studentX369 30

January 25 2025

2 6

It's 2024 and this is still something that doesn't exist? I'd just like to swap the Enter/Shfit+Enter behaviors since I find myself writing a lot of multi-line and custom procs and boy howdy it'd be nice if I could make Maple behave at least the littllest bit like, I dunno, every other product I own and use.

Why my out come is different by same method and sa...

Asked by: salim-barzani 1560

January 25 2025

0 0

i found solution of PDE but there is some different from my solution and paper solution so there is must be a mistake becuase he solved by maple too he mentioned in the paper i try to figure out but i can't see any mistake from my solution can anyone watch where i did mistake, i change some letter in finding parameter but they are same like p=k&h=A&n=p&w=n

here is paper solution

parameter-different.mw

How can I calculate a matrix of tensor contraction...

Asked by: scallopedpancake 25

January 23 2025

0 2

I'm calcuating an endomorphism in 2d dimensions. It is contructed out of a tensor contraction, for example, in 6-dimensions, the endomorphism is

K[mu,~nu] = LeviCivita[~alpha,~beta,~gamma,~delta,~upsilon,~nu]*C[alpha,beta,gamma]*C[delta,upsilon,mu]

I appreciate that, in terms of computation, this gets big quickly: it's something like O(exp) in time to sum over repeated indices in each matrix entry. Therefore, I thought, instead of putting the above expression in Define, I could make a matrix with unsummed entries, and then do the sums in parallel using Threads[Map](SumOverRepeatedIndices,...) but looking at my CPU usage and comparing execution times, it doesn't appear that this is working.

Is there any way I can more efficiently calculate these matrix entries?

Non consistent informations from Mapleprimes...

Asked by: mmcdara 7891

January 23 2025

3 0

This isn't the first time that I've seen a question that doesn't seem to have received a comment or answer, but which, when I click on the question title, turns out to have received one.
Here's the opposite phenomenon: a question appears to have two comments or answers, but none of them exist (9:38 GMT+1)

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String and parse on decimal number...

How can I find how Statistics:-Mean is coded?...

How to get a graph of this problem...

How to integrate it?...

How to get solution Soll11 for the reduced Liouvil...

Is it possible?...

How to simplify Eqs. (3), (5) and (6) and write in...

Maple Software Not Opening...

How find true parameter which satisfy pde?...

How can fix `[Length of output exceeds limit of 10...

Is there some way to avoid this behaviour?...

Customized Key Bindings?...

Why my out come is different by same method and sa...

How can I calculate a matrix of tensor contraction...

Non consistent informations from Mapleprimes...

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