I think I have come across with what it looks like a very basic bug using the member function. I get the error message: "Error, cannot determine if this expression is true or false: (3) < 100"  after the execution of the last line to the next code:

>Test:=Array(1..3,[1,2,3]);
>member(3,Test,'l');
>if l<100 then print("yes"); end if;

am I doing something wrong ?? I even checked the type of the variable 'l' and it is indeed an integer...

(1) Does ModuleCopy, when automatically called from Object,  really get the a shallow copy of the object

as the first parameter in its parameter list? See below, which is copied directly from ?object,create. The

ModuleCopy has first argument new::Dollar but ModuleApply only passes its two arguments not three. I

couldn't find a reference to this feature in the docs.

hey

I have wired problems with maple !!!

I run a code twice, I get 2 different answers !!!

I have uploaded the code ! just run it twicw and see the numerical values of alpha and beta at the end ! new_idea_gf.mw

In the final line, my output is in the form of tau-c*z. How do I switch the tau-c*z back to 

zeta, because I want to integrate T with respect to zeta.

Thank you. 

> restart;
> with(plots); 
> U := V(zeta)*exp(I*(k*tau-w*z));
> zeta := tau-c*z; 
> Uz := diff(U, z);
> Utau := diff(U, tau);
> Utautau := diff(Utau, tau);
> P := convert(U, trig);
> 
> A := abs(P)^2;
> B := evalc(A);

When I used Maple to solve 3 constants in 3 integral equations, fsolve cannot give me the numerial solutions. It copied the equations and showed me “fsolve（......）”. But if I change the positions of 2terms in the equations (for example a+b is rewritten as b+a), fsolve can give me the numerical solutions for the 3 constants. 

In most cases, I donot know the right order and it cannot give me the results. So what is the problem?...

I'm using Linearalgebra and suppose I have a 10x10 matrix. I want to find the closest element in each column of the matrix to 100. Any idea how to do it?

Being easy to use is nice, but being easy to learn with is better. Maple’s ease-of-use paradigm, captured in the phrases “Clickable Calculus” and “Clickable Math” provides a syntax-free way to use Maple. The learning curve is flattened. But making Maple easy to use to use badly in the classroom helps neither student nor instructor.

In the mid to late ‘80s,...

I need to find the Killing vectors of a metric.

I initiate the session as

> restart;
> with(DifferentialGeometry); with(Tensor); with(LieAlgebras);
> DGsetup([t, r, z, phi], M);

and enter my metric as

M > g1 := evalDG(-dt &t dt ...);

I do not have an unknown function in my metric but I have two free parameters (e.g. a and b).

I use

M > K1 := KillingVectors(g1, parameters = [a, b]);

hi 

if I have two partition Pi and Pi 'I want to know the decomposition of Pi' 

q2.mw

Hi!

I have a question on result storage of for loop.  The program in attached.

The program is relative complex, it is not necessary to look part 1.

The question is in part 2.

The result I proposed is:

r=([17400,12500],[13900])

but, the real result of r is：

r=table([1.0=[1.0,17400,12500],2.0=[2.0,13900],()=[]])

what should I do to modify the program?

I am writing a procedure that takes the "output" of a call to dsolve (with the options numeric and listprocedure and without specifying a range of integration) as an argument ('dsol') together with a minimally acceptable range of integration ('tf'). The output of the procedure is either the input 'dsol' itself, if dsolve has been able to integrate from 0 to 'tf', or a modified version where the initial conditions have been modified.

Say I want to integrate an ode system [u,v,w...

I have plotted a predator/prey system using the following code and would now like to plot the same with the initial value problem of y=200, x=1000, with the end result being a graph of that one trajectory, without the phase field.  How can I do this?  Thanks.

DEtools[DEplot] ([diff(x(t), t) = 2*x(t)*(1-0.1e-3*x(t))-0.1e-1*x(t)*y(t), diff(y(t), t) = -.5*y(t)+0.1e-3*x(t)*y(t)], [x(t), y(t)], t=0 .. 10, x = 0 .. 11500, y = 0 .. 200, [[x(0) = 1000, y(0) = 200...

Dear all

I tried to intgrate this problem

P:=(b8*Omega^8+b6*Omega^6)/(a10*Omega^10+a8*Omega^8+a6*Omega^6+a4*Omega^4+a2*Omega^2+a0);

using these limits

Omega_r1:=beta*Omega_c;
Omega_r2:=(2-beta)*Omega_c;

assume((2-2*beta)*Omega_c>0);
assume(a0>0,a2>0,a4>0,a6>0,a8>0,a10>0,b6>0,b8>0,beta>0);
P_I:=evalf(int(P,Omega=Omega_r1..Omega_r2)):

but the results was not useful I got (RootOf)

Hi everyone,

I want to draw a phase portrait of a particle to see it moving but I don't want to see its trajectory. I don't know how to explain, here is what I did:

restart;with(DEtools), with(plots), with(linalg):

g11:=1;g21:=g11;

z:=exp(I*((t/(2*Pi))+(Pi*j)));

f1:=evalc(Re((I/(2*Pi))*((g11/(subs(j=1,z)-(x(t)+I*y(t))))+(g21/(subs(j=2,z)-(x(t)+I*y(t)))))));

q1:=evalc(-1*Im((I/(2*Pi))*((g11/(subs(j=1,z)-(x(t)+I*y(t...

hi 

I determined this whole partition but I just want to have the finer the