In a reply to Markiyan Hirnyk's recent question on this topic, Alec Mihailovs posted solutions 
for  n=1..7 for the mean distance between random points in an n-cube.

I also 

Hi all,

 I am having a very hard time with numerical stability. I am solving system of ode's (7-coupled ode's) using dsolve(stiff) and then using spline function for interpolation and finally solving system of pde's (2-coupled pde's) using pdsolve for one time step and solving all again for the next step. the solution is not stable and it requires very fine/small time step. Is there any procedure/method to improve the stability? 

 What is the stability criteria of dsolve...

I have to evaluate several complex integrals involving square roots. Maple automatically assume the branch cut is all negative reals. Is there a way to change this? This would make my life alot easier! thanks!

I want to get the formula for frequency at resonance peak (   ω_n=ω*sqrt(1 - 2*ζ²)   ) in Maple 15, starting from the transfer function


                      G(s) := 1/(1+2*zeta*s/omega[n]+(1/(omega[n])^2)*s^2);


I wrote these lines but I haven't obtained the results I wanted:

                    'abs(G(j*omega))'=subs(s=i*omega,abs(G(s)));

At one point in earlier versions of Maple I was able to plot expressions such as y=4*a*x and the y axis would be incremented in units of a. Is there a way to do this in Maple 14?

> restart:
   with(DynamicSystems):
> sys := TransferFunction(1/((1+0.1*s)(1+0.002*s+0.0001*s^2)));
> BodePlot(sys,range=10^(-1)..10^(3));

 I get the following warning:

             Warning, transfer-function(s) are not rational-polynomial(s) in s



 Why?.. How can I make it work without any warning?

 Thanks everybody for help!

I'm running this numerical integration 14 hours continuously,without result.

The problem is the numerical integration

 evalf(int(F(q)*sin(q*Theta)/q)) assuming(0

This is taking forever.

Now,this is already done using Fortran (not time consuming at all),but the choice is not mandatory,so I'm using Maple 13.

Now,I think, to do this I have to do the integral using any other numerical method, evalf(int(,)) isn't good enough.

how to rewritten the PDEs to the matrix form like the following in Maple

I have attempted making a translation the Wolfram Mathematic's document: Singular Value Decomposition.
I present Problems in showing the arches of angles. Besides result do not correspond .

Plot_singular_value_.mw

Gracias

This is more of a blog entry, mostly a note to myself.

I wanted to generate a list of points on the surface of a deformed sphere. It turns out that Robert recently showed how to do that on a unit sphere.

http://www.mapleprimes.com/questions/35962-Limited-Random-Points-Plot-On-A-Surface#comment66936

Adapting his code is straightforward. So here is what I came up with. One proc generates the random points on the surface of the ellipsoid. Another proc generates...

Hi,

with(OrthogonalExpansions) not working in Maple 15 (work in Maple 14). What is the equivalent package for FourierSeries calculations?

Thanks in advance

Kamel Boughrara

 I have the following equation that I want to plot for theta and t with other parameter values in the equation fixed as below. But when I try to animate the solution I get an 'unable to plot' error message. What can I do to plot the equation, U(theta, t) below.

 U(theta, t) := 1/2/Pi+Q*sin(k*theta)+P*sin(m*theta)+1/4*(-I*Q*exp(1/2*k*(-sigma^2*k+2*I*theta...

Hi,

How can i delete a row in a (2D) Matrix?

Thanks,   (Mohsen)

evolf := proc(f);
h1 := z + f(x);
h2 := z - f(x);
h3 := z*f(x);
h4 := f(x)/z;
h5 := z+diff(f(x),x);
h6 := z-diff(f(x),x);
h7 := z*diff(f(x),x);
h8 := diff(f(x),x)/z;
h9 := subs(x=z, f(x));
test := [h1, h2, h3, h4, h5, h6, h7, h8, h9];
F = 0;
for i from 1 to 9 do
    F = F + 1/(1+exp(subs(x=0,test[i])-subs(x=0,f(x))));
end proc;            

Hi there,

I am using plot3d in worksheet mode to create a bunge of complex 3d-geometries containing "patches" (style = wireframeopaque) and wireframes (style = wireframe) representing the deformed and undeformed geometry of a system. I would like to export them as vector graphics since only then the results look nice enough to be used in a report.

When using Maple 12 rightclick->export->EPS, works nearly. Unfortunately the patches are not really...