I have an  ode system, and use  2 D Math  (I don't know how to copy here, so I type by hand)

x'(t) = -y(t) + x(t) (1 - x^2(t)  -  y^2(t)),

y'(t) = x(t) + y(t) (1 - x^2(t) - y^2(t)).

I would like to introduce  x(t) = r(t) cos(Theta(t)), y(t) = r(t) sin(Theta(t)) and manipulate the equations further.

The problem is the left hand side. In one case I obtain Dx(t), in the other case (r(t) cos(Theta(t))' without calculation on it.

I ask some help. Thanks.

Hi guys

 

How can i construct the standard vector e[i]. Where e[i] is a 4 dimensional vector with 0 in all entries apart from the ith which has ?

Hello there, Would appreciate if someone could illustrate the procedure to obtain, using the plot3d command, simply the solid bound by the given set of graphs. In other words, all superfluous areas are substracted. For example, for the cone z=sqrt(x^2 + y^2) & planes z=2 & z=4, I'd like to see just the solid bound by the planes and not what appears when the following commands are executed: a:=implicitplot3d(z = sqrt(x^2+y^2), x = -5 .. 5, y = -5 .. 5, z = -5 .. 5); b:=implicitplot3d(z = 2, x = -5 .. 5, y = -5 .. 5, z = -5 .. 5);

Hi Guys, i have a forloop problem.

I have a nxs matrix, where s=sum((k),k=1..n-1), so when n=3, s=3, when n=4,s=6 and so on.

I need to code each column number lexicographically for cartesian pair (i,j) where i<j, so when n=3, the columns would be

 

(1,2),(1,3),(2,3)

and when n=4 we have

(1,2),(1,3),(1,4),(2,3),(2,4),(3,4)

.

Is there a spherical harmonics package available anywhere ?

 

I may have to start using vector spherical harmonics and don't really feel like fighting with Maple, and the Legendre and Associated Legendre functions on my own.

 

v/r,

 

Hello, I have a question regarding the behavior of the numeric event division_by_zero. The documentation of ?event says that "A division of a non-0 number by 0 should signal a division_by_zero event. The default action is to return a correctly signed infinity, if possible, and otherwise an undefined. This event is also properly signaled when an attempt is made to evaluate a function at an infinite singularity, e.g., ln(0)." Yet, when using the default settings, I get the following output: > NumericEventHandler( division_by_zero = default ): > 1/0;

I been trying to make a Maplet that will solve some numerical analysis problems, those problems or indeen the solution of them are composed of iterations.

I would like to show such value iterations on a table in a Maplet interface, with no success.

for my logic, this should work.

Set('Table1',[[1,2],[3,4],[3,4]])

But I get an error telling me that the value is not settable.

It doesn't make sense to me to have a control that I can't modify its contents at runtime?

Any ideas about how to do this?

 

Thanks

Hey,

I am doing some ODEs and I met the following problem...

 

The original problem is

 

y(x)*(y(x)-2*x)*diff(y(x),x)=1;

 

and knowing the solutions contains efr function.

 

After several lines of calculation I got

Int(y^2*exp(1)^(y^2),y);

 

 

then maple gives me the answer

 

1/2*y*exp(y^2)+1/4*I*Pi^(1/2)*erf(y*I)

 

Hey

 

Can someone have a look at this

 

restart:

int(-m*(m-2)/(-1+m^3-2*m^2),m);

 

maple gives me

 

-sum(_R*(_R-2)/(3*_R^2-4*_R)*ln(m-_R),_R = RootOf(-1+_Z^3-2*_Z^2))

 

what dose this imply?

 

Thanks in advance

Hey

I have gone through all the maple videos that are linked to from the Maple Software, and was just wondering if anyone knows of any other places on the net where i can get maple videos, for free or paid?

I have learnt ten times more watching the videos than i did when using a book.

I still get stuck, but then i just come on here and ask.

 

Thanks All

Hello,

I am trying to get Maple to help me solve an integral equation.  I tried the solve command, which I suspected wouldn't work.  I was right, but I do not know how else to approach the problem.  Here is what I did:

 

solve(int(f(t), t = 1 .. x) = 5*x^2+7*x-3, f(t))

 

Of course this produced an error.  Any suggestions?  Thank you.

Hi everybody,
I would like to speed up my program because it is very slow for large input data
this program calculate arithmetic coding for input data

input:=[144,144,108,94,92,93,96,96,96,96,96,99,95,101,101,97,98,93,95,100,96,94,95,98,97,95]:
 R:=[seq(j,j=0..255)]:
# calculate frequency table 
p:=proc(x)
local k;
global cp:
cp:=0:
for k to N do
if (input[k]=x) then cp:=cp+1 fi
od:
cp/N
end:
G:=[seq(p(i),i=0..255)];

Hi,

My maple 11.02 appears to have some problem of lunching...

I can start Classical Worksheet though, but not Maple 11...

 

error:  cannot creat the java virtual mechine

 

I have tried to re-install Maple after uninstalling ,however it dose not help..

 

someone has any suggestion?

 

Thanks in advance

I hope to reimplement an expensive algorithm in Maple over windows. The suggestion I got is to write it in C and call it inside Maple. However, the algorithm itself is quite complicated and the linux version uses saclib2.1 library which provides many useful implementations of numerical routines. 

I therefore wonder if Maple provides its own C or C++ math libraries, so that I don't need to implement everything by myself?

Hi,

How do I ask maple to differentiate y^2+(x-c)^2=c^2 w.r.t.  x ?

 

it's defnitely not implicitdiff

I think I knew this before...then I just cant remember...

 

Thanks in advance.