After typing

with(LinearAlgebra):
avector:=Vector(3,symbol=a):
bvector:=Vector(3,symbol=b):
'a x b'=CrossProduct(avector,bvector)

Maple writes out

Hi,

iam trying to define a commutator rule (using the Physics package) but iam getting an error i do  not understand.

 

I have (quantum) operators like this: A_ij  i and j are numbers from 0 to 3

The commutator relation i want to define is: [A_ij,A_kl] = A_ilδ_jk - A_kjδ_il

 

My worksheet looks like this:

 

what am i doing wrong???

> restart;
> with(PDEtools);
> a := 3;
> U := u(r, t);
> wave := a^2*(diff(U, r$2))+(diff(U, r))/r) = diff(U,t$2));
> ics := u(1, t) = 0;
> bcs := diff(U, t) = piecewise(0<= r <b,-2, b<= r<1,0), u(r, 0) = 0;
> s := pdsolve(wave, {bcs, ics});

Error, (in pdsolve/sys) too many arguments; some or all of the following are wrong: [{u(r, t)}, {u(1, t) = 0, u(r, 0) = 0, diff(u(r, t), t) = -2}]

HI,is it possible to solve the ODE system (that I have uploaded) by adding events at a certain timestep, instead of reformulating the system for each step.The ODE system expresses two coupled movements y(t) and X(t). The current position of y(t) is controlled by a parameter which depends on values calculated in the previous step, while changing the sign for each step.Thank you! 

We have the following sequence of natural numbers
5, 7, 11, 13, 15, 19, 21, 29, 31, 33, 37, 39, 45, 55, 57, 63, 83, 85, 87, 91, 93, 99, 109,
 111, 117, 135, 163, 165, 171, 189, 245, 247, 249, 253, 255, 261, 271, 273, 279, 297, 325,
 327, 333, 351, 405, 487, 489, 495, 513, 567, 731, 733, 735, 739, 741, 747, 757, 759, 765,
 783, 811, 813, 819, 837, 891, 973, 975, 981, 999, 1053, 1215, 1459, 1461, 1467, 1485, 1539,
 1701, 2189, 2191, 2193, 2197,...

Hello:
    I  want to get the variational value of omega when KR[N]>0.2, but  the omega of my procedure remain the same,  how do I change my program to get the variational value of omega when KR[N]>0.2.

Thank you !

My procedure:
restart:
> Digits:=30;
>
> h0:=0.156;
> d:=0.32*h0;
> l:=2;
> h1:=h0-d;
> h2:=h0+d;
> h3:=0.6*h0;
> g:=9.8;
> d1:=1;

rsolve({g(m, n) = g(m − 1, n) + g(m, n − 1)},g,'genfunc'(a,b));

why no solution

So I have this long-ish for...do...end do loop that involves all sort of things incl. running an external program (via system() ) and fitting a nonlinear expression to the result; the loop iterating a parameter for the external calculation.

It would be swell if I could run something like a progress bar that tells how many cycles done and still to go. Even better if I could get at the value of a certain variable that indicates progress of the whole calculation (which is an optimization problem...

consider:

, R:  z <= sqrt(x^2+y^2+z^2)  ,  z<=sqrt(1-x^2-y^2)
what's wrong in my maple code:

>restart:

first:=int(exp((x^2+y^2+z^2)^(3/2)),x=sqrt(z^2-y^2)..sqrt(1-y^2-z^2)):
first:=simplify(first)assuming y>sqrt((z^2)/2)  ,  y< sqrt((1-z^2)/2);

I want to use a do loop to calculate some values of a function and print out the answers.
The result I want is of the form f(1)=17, f(2) = 21, etc. If I try

for j from 1 to 3 do
print( 'f(j)'=f(j) )
end do;

the j is not evalued and I get f(j)=17, f(j) = 21, etc.

I am now using Maple 15 and 16.

 

Thanks

Hi everyone, 

In my research project, I needed to evaluate a multi-variable integration.
int(int(sqrt(x^2+y^2),x),y)  , D: {(x^2+y^2 <= 2*y)  ,( y<=x ) , (x,y >0)}

Dear Users,

 

Maple is giving the result for the following integration as

 

int( x/(a^2-x^2), x)  = -ln(-a^2 + r^2)/2  

 

However, I presume the integral output should be -ln(a^2 -  r^2) /2 

 

Could any one comment on this issue.

 

Thanks for your attention.

as i do not know what is nu and omega in beta distribution, can i solve it by equating with mean of real data's mean and stardard derivation, to find nu and omega, but solution of nu is negative, 

i guess this method may be wrong, as result diagram is not fitted with real data

and weibull using this method, can not be solved and said solution lost

what is the correct way to draw it?

Hi,

    This is a silly quesiton, but I'm stuck on it. I have 4 vectors of length 16. I want to plot the 16 elements in different colours against the vector number (n=1..4). And assign the same colour each time to each element, i.e color( V[7, n=1] ) = colour( V[7, n=3]  ). How do I do this? 

 

Thanks!

I got this error message while attempting to compute Inverse matrix of symbolic function. 

Error, (in Normalizer) unable to allocate enough memory, computation aborted