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Hello people in mapleprimes,

I want to solve the next system of equation for B/A and C/A.

eq1:=A+B=F+G;
eq2:=k*(A-B)=kappa*(F-G);
eq3:=F*exp(I*kappa*a)+G*exp(-I*kappa*a)=C*exp(I*k*a);
eq4:=kappa*F*exp(I*kappa*a)-kappa*G*exp(-I*kappa*a)=k*C*exp(I*k*a);


But, though it is well-known, solve({eq1,eq2,eq3,eq4},{B/A,C/A})
does not work well, as the values I want to solve it for are
expressions: B/A and C/A not variables.

Then, you might thing the next works well.
eq:=subs({B=A/t,C=A/u},{eq1,eq2,eq3,eq4}):
solve(eq,{t,u});

But, this doesn't work well, with the answer was
only the ratio of t and u expressed as the following:

t = t, u = exp(I*k*a)*(exp(-I*kappa*a)*k^2-exp(I*kappa*a)*k^2-exp(-I*kappa*a)*kappa^2+exp(I*kappa*a)*kappa^2)*t/(4*kappa*k*exp(I*kappa*a)*exp(-I*kappa*a))

Isn't there nice way to solve the above system of equation, except that
sol1:=solve({eq3,eq4},{F,G});assign(sol1);
sol2:=solve({eq1,eq2},{A,B});assign(sol2);

Best wishes
taro

test.mw

restart; with(LinearAlgebra)

``

dF := -.525*exp(-7*t)+2.625*exp(-3*t)+.8*exp(-4*t);

-.525*exp(-7*t)+2.625*exp(-3*t)+.8*exp(-4*t)

(1)

``

e3 := `<,>`(1, 1, 1); E := proc (m) options operator, arrow; IdentityMatrix(m) end proc; beta := `<|>`(.1, .6, .3); S := `<|>`(`<,>`(-3, 1, 1), `<,>`(1, -5, 2), `<,>`(0, 2, -4)); S0 := -S.e3

beta := Vector[row](3, {(1) = .1, (2) = .6, (3) = .3})

 

S := Matrix(3, 3, {(1, 1) = -3, (1, 2) = 1, (1, 3) = 0, (2, 1) = 1, (2, 2) = -5, (2, 3) = 2, (3, 1) = 1, (3, 2) = 2, (3, 3) = -4})

 

S0 := Vector(3, {(1) = 2, (2) = 2, (3) = 1})

(2)

Z := `<|>`(x, y, z)

Z := Vector[row](3, {(1) = x, (2) = y, (3) = z})

(3)

ME := MatrixExponential(S+Typesetting:-delayDotProduct(S0, Z), t);

`[Length of output exceeds limit of 1000000]`

(4)

MEint := map(int, ME.dF, t = 0 .. infinity)

Error, (in int) wrong number (or type) of arguments: wrong type of integrand passed to definite integration.

 

`&beta;plus&Assign;solve`(Z = beta.MEint, Z)

"(RTABLE(18446744074195006390,VECTOR([x, y, z]),Vector[row])=RTABLE(18446744074193876574,VECTOR([.1, .6, .3]),Vector[row]).MEint) betaplus:=solve (RTABLE(18446744074195006390,VECTOR([x, y, z]),Vector[row]))"

(5)

``

1step- I want to integrate the (ME*dF) from t=0 to ∞ .

2step- Evaluate Z=<x,y,z> by solving Z=β*MEint.

Download test.mw

Hello,

I would like to ask for help with factorization, collection or decomposition of matricies. If I have the symbolic product of matrices:

A := Matrix(2, 2, {(1, 1) = a[11], (1, 2) = a[12], (2, 1) = a[21], (2, 2) = a[22]})

B := Matrix(2, 2, {(1, 1) = b[11], (1, 2) = b[12], (2, 1) = b[21], (2, 2) = b[22]})

then C:= A*B :

Matrix(2, 2, {(1, 1) = a[11]*b[11]+a[12]*b[21], (1, 2) = a[11]*b[12]+a[12]*b[22], (2, 1) = a[21]*b[11]+a[22]*b[21], (2, 2) = a[21]*b[12]+a[22]*b[22]})

and my question follows:

Can I factor this result C and get the imput matrices A and B ? Is any function for this operation ? I would like to use it for matrices 3 time 3 not only for 2 times 2.

Thank you for your help,

vidocq

 

After installing the 18.02 update to Maple 18, the inverse Laplace transform no longer works!

Hi,

 

  I am using maple on Windows 7. I edit .mw file by maplew.exe.

 

  When the source code becomes long, e.g. over 2000 lines, the editing resonse starts to be slow. I can try to edit in other software, e.g. editplus. Is there any way to let maplew works faster?

 

Thank you!

I have a long expression with different order derrivatives, that is written in form like that:

-(D[1](f))(x, y)

I'd like to transform it into standard maple form like:

diff(f(x,y),x)

Is there any special procedure to achieve this goal?

Hi all

Assume that we have a function, say f(t) and we want to substitute t in it where t is:

t=[0,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9,1]

by subs or other better command, how can we do it?

best wishes

Mahmood   Dadkhah

Ph.D Candidate

Applied Mathematics Department

sometimes, the maple server goes in a loop and runs full CPU. Waiting makes no difference. It just hanged. Even stopping the computation from the UI makes no difference (i.e. cliking on the "interrupt the current evaluation" button). Only way I found is go to task manager and terminate the mserver.exe by force.

The problem now is that I have to close Maple and start all over again. Since I can't start a new computation or do anything if the server is down.

I am just asking if there is a better way to do all this. For illustration, this int() command below hangs the server, so you can try the same thing I am seeing. This is on Maple 18.02, windows 7, 64 bit.

Make sure to save all your work before running this. This is just one example. I have many more where maple hangs like this (i.e. the interrupt does not terminate anything and the server keeps running)

y := 1;
z := 2 + x + y;
s := 1/2;
m2 := 5325;
m1 := 5279;
mz := 106055/10;

int1 =evalf(int(1/z^3 *(x + y + 2* x*y)* (1 + s^2/(2 *m2^2* z)) *exp(-(m2^2*x + m1^2*y)/s^2 + (mz^2 *(x + y + 2 *x*y))/(2* s^2* z)), x=0..1));

Surely this is a bug.

> 0^0;
                 1 
> sum( 0^m, m=0..infinity );
                 0

Hi experts

 

In a procedure with no declared parameteres I would like to return (print) the passed arguments (expecting Matrix structures) in a modified form along with the name of the symbol holding the structure passed as arguments.

 

That is, the procedure just iterates through the _passed arguments in a for-loop to display the name of the the passed argument (the symbol), a colon and then the modified matrix structure.

My problem is that when looping from i to _npassed arguments, refering to _passed[i] gives me the evaluated form.Tat is what I need to modify the structure but not to list the symbol name.

 

Say I wanted to print a transposed version of my passed matrices. Then I would call

M:=<<1,2>|<3,4>>;

myProc(M);

And the result I want would be

M: <<1,3>|<2,4>>

But I don't know if _passed holds the symbol names or just the evaluated versions of the passed arguments??

And theoretically the passed argument (assuming a matrix) could be the matrix structure put directly in the procedure call, in which case there is no symbol to refer to.

 

I hope you get my question and can help me out.

 

Thanks

Simon

 

So I'm having trouble using maple to find the relationship (formula) between two sets of data

 

I have time and current as t1, t2, t3...so on, and current.

 

Is there anyway to use maple to find it?

 
Hello
Please help solve this system

restart; 
B:=1: 
q:=1*10^3: 
l:=1: 
n:=4.7: 
M_F:=z->2*q*l*(z-l)-q*z^2/2: 
M_1:=z->piecewise((z<l), 2*q*l*(z-l)+l-z-q*z^2/2, (z>l), 2*q*l*(z-l)+l-q*z^2/2-l): 
M_2:=z->2*q*l*(z-l)+2*l-z-q*z^2/2: 
one_int:=z->int(B*(M_F(z)+X_1*M_1(z)+X_2*M_2(z))^n*M_1(z),z=0..2*l); 
two_int:=z->int(B*(M_F(z)+X_1*M_1(z)+X_2*M_2(z))^n*M_2(z),z=0..2*l);
value(one_int(z)); 
value(two_int(z)); 
eqs1:={value(one_int(z))=0,value(two_int(z))=0}; 
fsolve(eqs1);

 

hello, i went solve these equation ,with a & b take any value

b*x*ln(x)-x*ln(a)+a=0

thank you

In this document, I think that is the relevent section. But I couldnt understand it.

 

I want something like this

>plot(sin(x),color=yellow);

>plot(sin(x),color=organe);

>plot(sin(x),color=red);

>plot(sin(x),color=green);

>plot(sin(x),color=ABC); # error

>plot(sin(x),color=CBA);# error

optional, but works fine within a given sets of choices.

 

How do I write a procedure like that?

 

Thanks!

st6.mw,st7.mwI want to obtain the analytical solution for this PDE by maple   diff(T(x, y, z), x, x)+diff(T(x, y, z), y, y)+diff(T(x, y, z), z, z)+A*exp(-8*x^2/a^2)*cosh(alpha*((1/2)*b+y)) = 0    . But I can not do it. Please help me

((d^2)T/dx^2)+ ((d^2)T/dy^2)+ ((d^2)T/dz^2)=-A*Q(x,y,z)

Where   0 <x<a ,  0 <y<b  ,  0 <z<l

With the boundary conditions:

(dT(0,y,z)/dx)=n-T(0,y,z)    (dT(a,y,z)/dx)=n-T(a,y,z)   (dT(x,0,z)/dy)=n-T(x,0,z)

(dT(x,b,z)/dy)=n-T(x,b,z)     (dT(x,y,0)/dz)=n-T(x,y,0)    (dT(x,y,l)/dz)=n-T(x,y,l)

where n is constant and A is set of parameters.

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