Hi 

I am working on a physics simulation and I modeled an electric field in the space.

For this purpose I wrote an algorithm on Maple that returns me a list composed by the following lists:

[[x,y,z],[Ex,Ey,Ez]] in which x,y and z represent different positions in the space and Ex,Ey and Ez the components of the vector E in these points.

How can I plot these vectors with maple?

I was curious about converting between the different ways of writing a derivative in maple for the standard GUI.

I can convert y' to D(y)(x) but I cannot directly convert y' to the form d/dx y(x) unless I go to the
tools->options->display and change the typsetting level to maple standard and reprocess the line.  We are stuck with either one form or the other but not both without having to adjust the typsetting level in...

Dear All

Suppose that you have a pdf for the number of request receiving to a system with mean m. Suppose that it is not a common distribution.

Is it correct that there is a time between request with a specific distribution and the mean value of distribution is 1/m.

Is there any math rule that can prove it?

Best Regards,

Saeid

I've got the problem of warnings polluting my text outputs.

If I use interface(warnlevel = 0) the warnings are suppressed in the terminal but not in the files exported by the writeto command.

A sample:

> restart;with(CodeGeneration); with(plots); with(ListTools); with(FileTools);
> Matlab(u(1) = 3);
Warning, the function names {u} are not recognized in the target language
cg = u(1) == 3;
> interface(warnlevel = 0); Matlab(u(1) = 3);

I found following bug:

p := proc (k) sum((-1)^n*n/(factorial(k-n)*factorial(n)), n = 1 .. k) end proc; 

sum(p(k), k = 1 .. 1); 

sum(p(1), k = 1 .. 1); 

p(1)

Results must be same, but output is 0 (bug!), -1 (correct), -1 (correct)

Dear All,

Hi. I am interested to find the pdf of this moment function: phi(t) = exp(a * b / p (e^(a*t) -1))

This is a moment of random variable Y = aX where X is a Poisson random variable with rate (a*b/p)

I want to know is it possible to find a pdf from its moment in maple?

If so how?

Best Regards,

Saeid

Sorry to bother you again,fellow primers.A few days ago I asked a similar kind of q.,but here is some change, & I'm stuck again.

int(p^(D-2)/(exp(beta*p)-1), p = 0 .. infinity) assuming beta::positive, D::posint #D>0 & is an integer,this two are the only restriction on D,nothing else.

 I'm not getting any result (correct/incorrect).

The  result is  GAMMA(D-2)*Zeta(D-2)/beta^(D-2).  #Zeta is the Riemann zeta function.

can someone give help or a hint on how to overcome the faulty result in the pdsolve problem with radiation bc described in the following worksheet? I tried also with different method, but no success. the result from pdsolve makes physical no sense, because under pure radiation bc (h=0) the body should cool down and not heat up!

maple_heat_rad_pdsol.mw

thanks :-)

btw, the problem was reported befor, see:

How to compute the highest total degree of a polynomial in which a variable, say x, appears?

For example, f := x^2*y+3*x*y^2+x^3*y^3-x^5+y^4*z^5;
then the highest total degree in x is 6.

The degree command does not seem to do what I would like to do, since degree(f,x) will give 5 instead.

Thank you in advance.

Dyson_Mclean_V3.mw

Dyson_Mclean_V5.mw

Hi All,

I have a question that I see has been seldom discussed except certain posts by Mr. Lopez. This concerns the estimation of optimum parameters of the solution of a system of differential equations to fit experimental data. I referred to the Maple document provided by Mr. Lopez on the Maplesoft website.

Good morning.

I want to do a program in a worksheet that it can recall other workeet for plotting with display.

I don´t know how can recall other worksheets.

Please help me.

P.D.: I send a worksheet 01-06-2011-robot-man.mw

Hi,

I am new to Maple so I don't know if this is expected behavior or simply a setting or command I need to set.

When I calculate (12x²y²)/4xy, I get (3x²y²)/xy instead of the simplified 3xy. Is this normal?

Thanks,

Perry

Hi,

I am tring to solve two coupled pde's with piecewise/Heaviside conditions. I am puzzled with the maple error...Rhop, Rhos are constants n given some values..

> pde_sys:=[diff(c(m,t),t)=(2/m)*diff(c(m,t),m)+diff(c(m,t),m,m)-(convert(piecewise(d(m,t)<Rhop,(Rhop-d(m,t))*d(m,t)*c(m,t)),Heaviside)+(Rhos-d(m,t))*c(m,t)*convert(piecewise(d(m,t)>Rhop,Rhop,d(m,t)),Heaviside)), diff(d(m,t),t)=convert(piecewise(d(m,t)<Rhop,(Rhop-d(m,t))*d(m,t)*c(m,t)),Heaviside...

Like when I type

1/2^2;

it gives

1/4

but if I type

0.5^2;

it gives

0.25

I want it to consider 0.5 as 1/2, because sometimes I make computations on large equations and I want to have access to the symbolic output, not the numeric output.

Hello all,

I am trying to solve a pde system with piecewise conditions numerically but unsucessful. Here's what i am doing:

> restart;

> sys:=[diff(c(x,t),t)=v(x,t)*diff(c(x,t),x$2),diff(v(x,t),t)=piecewise(c(x,t)>v(x,t),c(x,t)*diff(v(x,t),x$2),0)];

> bc:={c(0,t)=2,c(1,t)=1,c(x,0)=0,v(0,t)=1,v(1,t)=2,v(x,0)=0};

> sol:=pdsolve(sys,bc,type=numeric,time=t);

I am getting the following error.......

Error, (in pdsolve/numeric/process_PDEs...