MaplePrimes Questions

Dear Mapler

I want to find all real and complex solutions to the following equation. then calculate the omega based on these values and finally select the present the omega with the smallest imaginary part.

with(SignalProcessing):

n:=8;

kk:=FFT(GenerateJaehne(n,1));

#params:= [p,    s, nu,   rho, h,    sigma, C1[1], C1[2], C2[1], C2[2], k1,  k2,  m1[1], m1[2], m2[1], m2[2] ]
 params:= [1e-7, 0, 1e-6, 1e3, 1e-2, 0,     5e-4,  5e-4,  5e-4,  5e-4,  1.4, 1.4, 1+I,   1+I,   1-I,   1-I   ]:

for i from 1 to n do
    x:=kk[i]:
    mm[i]:=[solve(
             eval(
                  ( (x*h)*( (y*h)*sinh((x*h))*cosh((y*h))-(x*h)*cosh((x*h))*sinh((y*h)))*(1+s*(x*h)^2)
                    +p*(-4*(x*h)^2*(y*h)*((x*h)^2+(y*h)^2)+(y*h)*((y*h)^4+2*(x*h)^2*(y*h)^2+5*(x*h)^4)*cosh((x*h))*cosh((y*h))
                    -(x*h)*((y*h)^4+6*(x*h)^2*(y*h)^2+(x*h)^4)*sinh((x*h))*sinh((y*h))))
                  /((x*h)^2*(y*h)*cosh((y*h)))
                 , [p=params[1], s=params[2], h=params[5] ]), y
            , AllSolutions=true)]:
    print(kk[i]);
    print(mm[i]);
    for j from 1 to nops(mm[i]) do
        omega[i][j]:=eval(-I*nu*((x*h)^2-mm[i][j]^2), [nu=params[3],h=params[5]]);
        print(omega[i][j]);
    od:
    print(`======`);
od:

Given two terms in expression of type  `+` where the first is rational and the second is not, I wanted to combine both under on common denominator to obtain one term (not `+` any more).

I expected that combine will do that.

restart;
expr:=A/B+C;
combine(expr);

But the above leaves the original expression as is. Ofcourse I can just do

numer(expr)/denom(expr);

Here is screen shot

My question is why combine does not do that automatically? For reference, Mathematica command Together is the equivalent to Maple combine and this is what it does

Which is what one would expect to happen. 

I am just trying to understand the logic why Maple's combine did not work as one would expect. That is all. I looked at help and tried different option to combine, but non worked.

Is there  a specific type name for vectors in Physics[Vectors]?  Specifically, Let's say we want to write a proc whose argument is expected to be a (Physics) Vector, as in  these (trivial) demos:

with(Physics[Vectors]);

f := proc(a_::???)
    return a_ . a_;
end proc:

g := proc(a_::???, b_::???)
    return a_ &x b_;
end proc:

What do we put in place of "???".

I want to create and modify the same worksheet at different times on two different computers in two different locations.

To avoid transferring files between the two machines, it seems most convenient to reference all objects within Maple cloud.

I am a beginner at this and have several questions:

1) I have downloaded the DirectSearch package as directed in help text but the only result from issuing the command kernelopts(toolboxdir) is " ".

How can I establish a path which enables my worksheet to execute commands within this package?

2) How can my worksheet invoke procedures within my .mla file referencing only objects in Maple cloud?

 How can I update (save and delete procedures) within my .mla file? 

Maple knows how to obtain differntials using D.

So typing  D(x*y) it gives   D(x)*y+x*D(y)

But what I want is given as input  D(x)*y+x*D(y) have Maple return back D(x*y)

Nothing I tried work. I tried simplify and convert(...,D) 

I am looking for a function that takes an expression with differentials like the above output, and return, if possible ONE differnetial in the form  D(  f(x,y) )

What I mean, given as INPUT any of these expressions on the RHS in the image below

To return back  the  D(...)  in the LHS above. I know Maple can do it going from the LHS to the RHS. But I want the other way around.

Does Maple support such operations?

Maple 2022.1

If I have a list say 

L:=[1,"2","3",4,5,"6",7,8,9,"10"]

Now i would like to have fuction which takes L as input say    split(L)

and would return two list one with characters from that namely ["2","3","6","10"] and another of integers [1,4,5,7,8,9] like this 

The list will have characters and integers only

Kind help it will be acknowleged

Q1: clicking on a variable in the attached I get

What does it mean and how can I fix that when it happens?

Initialisation_diagnostics_error.msim

Q2: Why are initial conditions which are set to "Ignore" listed as "Guess"?

I intend to use the initialization diagnostics to filter a model for components that have initial conditions set. In the attached example (excerpt from a larger model), this does not work the way I want it to (i.e. I don't want P1 to be listed a guess).

Init_diagnostics_ignore_listed_as_guess.msim

Q3: The app seems to be a powerfull tool. Is it explained somewhere how to use the app to debug a model?

Given a diagonal metric of signature (++- -)  for example the diagonal elements are [1,1,-1,-1], then how to find the Dirac gamma matrix in the standard representation or any representation.

restart;
with(LinearAlgebra);
with(plots);
NULL;

EqBIS := proc(P, U, V) local a, eq1, M1, t, PU, PV, bissec1; a := (P - U)/LinearAlgebra:-Norm(P - U, 2) + (P - V)/LinearAlgebra:-Norm(P - V, 2); M1 := P + a*t; eq1 := op(eliminate({x = M1[1], y = M1[2]}, t)); RETURN(op(eq1[2])); end proc;
NULL;
A := <4, 8>;
B := <4, 2>;
C := <1, 4>;
EqBIS(A, B, C);
NULL;

Cen := proc(M, N, R) local eq1, eq2, sol; eq1 := EqBIS(M, N, R) = 0; eq2 := EqBIS(N, M, R) = 0; sol := simplify(solve({eq1, eq2}, {x, y})); RETURN([subs(sol, x), subs(sol, y)]); end proc;
Cen(A,B,C):

CircleParm := t -> [(-t^2 + 1)/(t^2 + 1), 2*t/(t^2 + 1)];
P1 := Transpose(convert(CircleParm(1/4), Vector));

P2 := Transpose(convert(CircleParm(5), Vector));
P3 := Transpose(convert(CircleParm(-1/10), Vector));
P4 := Transpose(convert(CircleParm(-3/2), Vector));

C1 := Transpose(convert(Cen(P1, P2, P3), Vector));
Pts := [P1, P2, P3, P4, C1];

display(implicitplot([x^2 + y^2 - 1], x = -2 .. 2, y = -4 .. 2, colour = [blue], scaling = constrained), pointplot(Pts, symbolsize = 16));
Error, (in plots:-pointplot) incorrect number of coordinates in points data
NULL;Why this error. Thank you.

How relabel only one particular vertex of G of my choice. others will remain as it is

Function I want to create 

V:=Vertices(G):

Relabel:=proc(Graph::G,S,K)

I want to relabel only that particalur S subset V of G where S is list with say the K is a list of labels to be assigned the corrsponding vertices i paased in S. 

end proc;

Where v:=V[i] the vertex , k can be a character like       a or 1 or [1,2,3,4] or anything

To Maple support,. 

fyi,

internal error generated on this ode when trying odetest
 

interface(version);

`Standard Worksheet Interface, Maple 2022.1, Windows 10, May 26 2022 Build ID 1619613`

restart;

ode:=x^3*diff(y(x),x$3)+x^2*diff(y(x),x$2)-3*x*diff(y(x),x)+(x-1)*y(x)=0;
sol:=dsolve(ode,y(x),'series',x=0):
odetest(sol,ode,'series','point'=0);

x^3*(diff(diff(diff(y(x), x), x), x))+x^2*(diff(diff(y(x), x), x))-3*x*(diff(y(x), x))+(x-1)*y(x) = 0

Error, (in odetest/series) complex argument to max/min: 1/4800*((-79*I+3*83^(1/2))*3^(1/2)+9*I*83^(1/2)-79)*(316+12*83^(1/2)*3^(1/2))^(2/3)+1/12*I*(316+12*83^(1/2)*3^(1/2))^(1/3)*3^(1/2)-1/12*(316+12*83^(1/2)*3^(1/2))^(1/3)+20/3


 

Download problem_odetest_july_23_2022.mw

 

Update 2 years later

FYI, This error is still not fixed in Maple 2024

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 1793 and is the same as the version installed in this computer, created 2024, August 25, 9:6 hours Pacific Time.`

Order:=4;
ode:=x^2*diff(y(x),x$2)+x^2*diff(y(x),x)+y(x)=0;
maple_sol:=dsolve(ode,y(x),'series','point'=0);
odetest(maple_sol,ode,'series','point'=0);

4

x^2*(diff(diff(y(x), x), x))+x^2*(diff(y(x), x))+y(x) = 0

y(x) = c__1*x^(1/2-((1/2)*I)*3^(1/2))*(series(1-((1/2-((1/2)*I)*3^(1/2))/((1/2-((1/2)*I)*3^(1/2))^2+3/2-((1/2)*I)*3^(1/2)))*x+((3/2-((1/2)*I)*3^(1/2))*(1/2-((1/2)*I)*3^(1/2))/(((1/2-((1/2)*I)*3^(1/2))^2+3/2-((1/2)*I)*3^(1/2))*((1/2-((1/2)*I)*3^(1/2))^2+9/2-((3/2)*I)*3^(1/2))))*x^2-((5/2-((1/2)*I)*3^(1/2))*(3/2-((1/2)*I)*3^(1/2))*(1/2-((1/2)*I)*3^(1/2))/(((1/2-((1/2)*I)*3^(1/2))^2+3/2-((1/2)*I)*3^(1/2))*((1/2-((1/2)*I)*3^(1/2))^2+9/2-((3/2)*I)*3^(1/2))*((1/2-((1/2)*I)*3^(1/2))^2+19/2-((5/2)*I)*3^(1/2))))*x^3+O(x^4),x,4))+c__2*x^(1/2+((1/2)*I)*3^(1/2))*(series(1-((1/2+((1/2)*I)*3^(1/2))/((1/2+((1/2)*I)*3^(1/2))^2+3/2+((1/2)*I)*3^(1/2)))*x+((3/2+((1/2)*I)*3^(1/2))*(1/2+((1/2)*I)*3^(1/2))/(((1/2+((1/2)*I)*3^(1/2))^2+3/2+((1/2)*I)*3^(1/2))*((1/2+((1/2)*I)*3^(1/2))^2+9/2+((3/2)*I)*3^(1/2))))*x^2-((5/2+((1/2)*I)*3^(1/2))*(3/2+((1/2)*I)*3^(1/2))*(1/2+((1/2)*I)*3^(1/2))/(((1/2+((1/2)*I)*3^(1/2))^2+3/2+((1/2)*I)*3^(1/2))*((1/2+((1/2)*I)*3^(1/2))^2+9/2+((3/2)*I)*3^(1/2))*((1/2+((1/2)*I)*3^(1/2))^2+19/2+((5/2)*I)*3^(1/2))))*x^3+O(x^4),x,4))

Error, (in odetest/series) complex argument to max/min: 9/2-1/2*I*3^(1/2)

 


 

Download odetest_error_series_august_2024.mw

 

Will check again in 2-3 years and I am sure this bug will still not be fixed.

 

He Seniors, How to increase the quality of graph by puting command in ploting command according to required desire

Graph_qaulity_help.mw

Hi,

I found a bug in convert, please help me if you know a solution.

When we use the code

convert(U(xi)^2*y(xi)^5,list);

we get 

[U(xi)^2, y(xi)^5]

but when we use

convert(U(xi)^2,list);

we obtain

[U(xi),2]

while I expect the following result:

[U(xi)^2]

* "convert" is one part of my code for solving a problem. Sometimes there are cases that just exist one function instead of >1.

Since I want to keep my codes general, hence I need [U(xi)^2] in response to convert(U(xi)^2,list).

Thanks in advance.

A polynomial divided by another polynomial of lower degree. I want to find the remainder and quotient. How do I get.

The question is what should I add to the numerator get perfect division when x-3 x  -12 x+19 is divided by x2+x-6.

I shd get the answer as 2x+5 to be added since the remainder is -2x-5.   (Note that x-3 x  -10 x+24 is excatly divided by 2+x-6.

Can any one state the code to get the answer.

Quotient ( ) and Remainder (  ) codes , i tried, donot know how to use them.

Thanks for help. Cheers. RK


I'm using Maple 2021, and my Euler-Lagrange equation is coming out with a R[0] term that should not be there. I want to know what is causing this error and how I can fix it.

restartNULL

Lagrangian

 

Leq := (1/2)*R^2*[-cosh(rho1(tau)^2)*(diff(t(tau), tau))^2+(diff(rho1(tau), tau))^2+sinh(rho1(tau)^2)*(diff(theta1(tau), tau))^2]+(1/2)*R^2*[-cosh(rho2(tau)^2)*(diff(t(tau), tau))^2+(diff(rho2(tau), tau))^2+sinh(rho2(tau)^2)*(diff(theta2(tau), tau))^2]-(1/2)*k*rho1(tau)^2-(1/2)*k*rho2(tau)^2-(1/2*(tanh(rho2(tau)-rho1(tau))+1))*(rho2(tau)-rho1(tau))^2; L := subs({diff(rho1(tau), tau) = var4, diff(rho2(tau), tau) = var6, diff(t(tau), tau) = var2, diff(theta1(tau), tau) = var8, diff(theta2(tau), tau) = var10, rho1(tau) = var3, rho2(tau) = var5, t(tau) = var1, theta1(tau) = var7, theta2(tau) = var9}, Leq)

(1/2)*R^2*[-cosh(rho1(tau)^2)*(diff(t(tau), tau))^2+(diff(rho1(tau), tau))^2+sinh(rho1(tau)^2)*(diff(theta1(tau), tau))^2]+(1/2)*R^2*[-cosh(rho2(tau)^2)*(diff(t(tau), tau))^2+(diff(rho2(tau), tau))^2+sinh(rho2(tau)^2)*(diff(theta2(tau), tau))^2]-(1/2)*k*rho1(tau)^2-(1/2)*k*rho2(tau)^2-(1/2)*(-tanh(-rho2(tau)+rho1(tau))+1)*(rho2(tau)-rho1(tau))^2

(1.1)

Time Equation

 

epr11 := diff(L, var2); epr12 := diff(L, var1); epr13 := subs({var1 = t(tau), var10 = diff(theta2(tau), tau), var2 = diff(t(tau), tau), var3 = rho1(tau), var4 = diff(rho1(tau), tau), var5 = rho2(tau), var6 = diff(rho2(tau), tau), var7 = theta1(tau), var8 = diff(theta1(tau), tau), var9 = theta2(tau)}, epr11); epr14 := subs({var1 = t(tau), var10 = diff(theta2(tau), tau), var2 = diff(t(tau), tau), var3 = rho1(tau), var4 = diff(rho1(tau), tau), var5 = rho2(tau), var6 = diff(rho2(tau), tau), var7 = theta1(tau), var8 = diff(theta1(tau), tau), var9 = theta2(tau)}, epr12); epr15 := diff(epr13, tau); teq := epr15-epr14 = 0

2*R*[0]+(1/2)*R^2*[-4*rho1(tau)*(diff(rho1(tau), tau))*sinh(rho1(tau)^2)*(diff(t(tau), tau))-2*cosh(rho1(tau)^2)*(diff(diff(t(tau), tau), tau))]+(1/2)*R^2*[-4*rho2(tau)*(diff(rho2(tau), tau))*sinh(rho2(tau)^2)*(diff(t(tau), tau))-2*cosh(rho2(tau)^2)*(diff(diff(t(tau), tau), tau))] = 0

(2.1)

NULL


 

Download Maple_Help_Example.mw

 

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