restart;
evalf(Int(cosh(t)/(cosh((17/15)*t)+cosh(t)), t = 0 .. infinity));

5.210624833

evalf(int(cosh(t)/(cosh((17/15)*t)+cosh(t)), t = 0 .. infinity));

2.720144439

I am trying to setup a general metric with the Physics package.  The metric is composed of the Minkowski metric plus the product of two null vectors. Here is the code:

retstart;

with(Physics);

Define(l[mu],eta[mu,nu]);

eta[mu,nu] := rhs(g_[]);

Setup(g[mu,nu]=eta[mu,nu]+l[mu]*l[nu]);

I get the following error:

Error, (in Physics:-Setup) wrong argument: g[mu, nu] = l[mu]*l[nu]+(Matrix(4, 4, {(1, 1) = -1, (1, 2) = 0, (1, 3) = 0, (1, 4) = 0, (2, 2) = -1, (2, 3) = 0, (2, 4) = 0, (3, 3) = -1, (3, 4) = 0, (4, 4) = 1}, storage = triangular[upper], shape = [symmetric]))

My plan is to apply the rule g[~mu,~nu]*l[mu]*l[nu] = 0 and calculate the Christoffel symbols using the metric.

I am trying to use the Physics package because the DifferentialGeometry package seemed focused on Newman-Penrose.  I will not be using NP for the calculations, only a strict calculation of the Einstein field equations from the given metric.

Thank you.

Hi everybody,

In quantum mechanics, I want to draw the wave  of the electron in the hydrogen atom.  So in 3D, you will have a cricle and along the circle, there will be a cosine function that will meet after a full cercle (the standing wave that is possible).  The blue one and the red one at the same time.  But in 3D

The closest that I come to succes is with this commands:

But as you will see, the wave end at the same place as it started.  But instead of going in a cercle, is as a funny shape.

Thank you in advance for you trouble.

--------------------------------------
Mario Lemelin

Maple 18 Ubuntu 13.10 - 64 bits
Maple 18 Win 7 -  64 bits
messagerie : mario.lemelin@cgocable.ca
téléphone :  (819) 376-0987

AOA... There are three question

1. I want to convert exp(Iota*theta) into ternometric function i.e., 

exp(Iota*theta) = cos(theta)+Iota*sin(theta)

Is there any comand pl help...

2. Also i want to rationalize the complex number...

3. I want to seprate real and imaginary parts of a comaplex numbers

I try to sort a polynomial using the graded reverse lexicograpic order. According to the Documentation this is achieved via tdeg.
So here is what i tried:

with(Groebner):
sort( x+y+z, order = tdeg(x,y,z));

or

sort(x+y+z, [x,y,z], tdeg);

In both cases maple returns "x+y+z" instead of the expected "z+y+x". What am i doing wrong?

With the package VectorCalculus we can study the speed and acceleration to their respective components. Considering the visualizaccion and algebraic calculations and to check with their respective commands. Both 2D and 3D.

Velocidad-Aceleració.mw     (in spanish)

Lenin Araujo Castillo

Physics Pure

Computer Science

Hello,

I have to simplify a piecewise function and Maple gets a more complicated solution than needed.




I don't know how to handle this kind of problems with Maple?
I don't understand why Maple doesn't see this?
Am I doing something wrong?

Thanks in advance for your help / advice.


# the code of my example
restart:
Mf(x):=piecewise(x<=L/2,1/2*x*F,x>1/2*L,1/2*x*F-F*(x-1/2*L));
# Make a dimensionless function:
# -    Mf(x):= Mf(xi)*F*L
# -    variable ξ  ( xi:=x/L )
eq[1]:=Mf(xi)*F*L=Mf(x);
Mf(xi):=solve(eq[1],Mf(xi));
Mf(xi):=subs(x=xi*L,Mf(xi));
# F is the Force and L is the Length of the beam:
Mf(xi):=simplify(Mf(xi)) assuming F>0,L>0;
print("When I simplify this function by hand it will be");
Mf(xi):=piecewise(xi<=1/2,1/2*xi,xi>1/2,-1/2*xi+1/2);

Hello, everyone. I faced some promblems on maple. Hope you can help me.

I want to set up the commutation rules like Pauli sigma matrix in Physics Packages,

but failed to get the correct one.

Here is my maple code:

restart;
with(Physics);
Setup(mathematicalnotation = true);

Setup(quantumop = {Q}, algebrarule = {%AntiCommutator(Q[j], Q[k]) = 2*KroneckerDelta[j, k], %Commutator(Q[j], Q[k]) = 2*I*(Sum(LeviCivita[i, k, l]*Q[l], l = 1 .. 3))});

Commutator(Q[1], Q[2]);
                              
AntiCommutator(Q[1], Q[2]);
                              
AntiCommutator(Q[1], Q[1]);
                              
Commutator(Q[1], Q[1]);

In fact, Commutator(Q[1], Q[2]) give a incorrect result 0 while the correct answer is  2*I*Q[3].

Do anyone know how to resolve this?

Hello,

can I remove tick marks from axis in plots ?

Hi Everybody.

Doing some calculation in quantum mechanics, I stuble on that integral:

I see immediately that the answer is 1/2.  But Maple 18 cannot give an answer other than a limit that he cannot evaluate.  I even try assumption that p and hbar are realcons.  I get infinity.

Any idea?

Thank you in advance for your help.

--------------------------------------
Mario Lemelin

Maple 18 Ubuntu 13.10 - 64 bits
Maple 18 Win 7 -  64 bits
messagerie : mario.lemelin@cgocable.ca
téléphone :  (819) 376-0987

Hello,

Can anyone explain to me why there is a difference between:

f := int((A*sin(omega*t+phi)-B*sin(omega*t))^2, t);

and the expanded version:

f := int((A*sin(omega*t)*cos(phi)+A*cos(omega*t)*sin(phi)-B*sin(omega*t))^2, t);

Thanks

Hi,

Is there any difference between

Matrix(4,5,(K,C)->K+C);

and

Array(1..4,1..5,(K,C)->K+C);

Say if I have a very 'complicated' procedure myfunc(K,C) that takes two options, but it runs all dependently.

Matrix(4,5,(K,C)->myfunc(K,C));

and

Array(1..4,1..5,(K,C)->myfunc(K,C));

Which one is more efficient? The final ouput of each run from myfunc is just a integer value.

The reason I am asking it that i think both runs on a 'single' thread (core) as CPU usage is always very low, around 15-20%.

If I look at the task manager, some cores (threads) arent doing anything.

Is there anyway to speed things up?

Thanks,

I am trying to get a Fourier transform of a Gaussian:

so I say

and get

The Fouriertransform of a Gaussian is well known and the result I expect is something like

exp(1/2*sigma^2*omega^2)

ignoring normalizations & other factors. I know that I can add functions to inttrans, but I kind-of expected inttrans[fourier] to know how to transform a Gaussian, it is a commonly used transformation. Even if I set phi0 to 0 it does not produce anything useful.

???

Mac Dude

Hi

coeff dosn't work correctly in maple 17

Here is the code

restart;

E := m1*(diff(x1(t), t, t))+3*k*x1(t)-k*x3(t)-k*x2(t);
coeff(E, x1(t));
Error, unable

the coeff of diff(x1(t),t,t) and x2(t) and x3(t) can be determined and are true, but the coeff of x1(t) can not be determined??!!!!!!!!!!!!