Dear all,

I have one quetion. I have written maple code based on Dr.Robert J. Lopez's one.

Here is my code.

> q1 := diff(x(t),t) = -a*x(t)*y(t) + b*z(t);

q2 := diff(y(t),t) = -a*x(t)*y(t) + b*z(t);

q3 := diff(z(t),t) =  a*x(t)*y(t) - b*z(t);

q4:=k(t)=x(t)*y(t)/z(t);

ic := x(0)=10,y(0)=10,z(0)=0;

C := < I put Experimental data….>:

> SS := proc(a,b)

local F, V;

if not type([a,b],['numeric','numeric']) then return 'SS'(a,b);

elif a<0 or b<0 then return 1e100;

end if;

F := dsolve(eval({q1,q2,q3,q4,ic},{:-a=a,:-b=b}),[x(t),y(t),z(t),k(t)],numeric, output=Array([seq(k,k=0..N)]));

V := convert(Column(F[2,1],5),Vector);

Norm(V-C,2);

end proc:

 I just put one more equation -eqn4. it is not differential equation.

I currently have error massage from maple. Could you let me know how I solve the equations in this case?

Thanks.

Hello,

Since I was working in Matlab with Galerkin method which implies periodic boundary conditions I was wondering how to implement this in maple.

I tried this:

restart;

pde2 := diff(u(x, t), t)+3*(diff(u(x, t)^2, x))+diff(u(x, t),x$3) = 0

IBC := {u(0, t) = u(2, t), u(x, 0) = sech(50*(x-1/2))^2+2*sech(30*(x-1))^2, (D[1](u))(0, t) = (D[1](u))(2, t), (D[2](u))(0, t) = (D[2](u))(2, t)}

pds := pdsolve(pde2, IBC, numeric, time = t, range = 0 .. 2)

But it's telling me: 

Error, (in pdsolve/numeric/process_IBCs) initial/boundary conditions can only contain derivatives which are normal to the boundary, got (D[2](u))(0, t)

So what's wrong?

following commands on my computer got an error.

restart;
with(LinearAlgebra):
A:=Matrix([[1,3],[2,5]],datatype=float):
b:=Vector([1,1],datatype=float):
LinearSolve(A,b,method=hybrid);
Error, (in SWcallhybrid[1]) param 4 should be an rtable

any suggestion is appreciated.

win7, 12.02

Hi,

I'm sorry, a few das ago I asked about it. Problamy my question was unclear.
I've decieded asking again.

I need a prcocedure (or contitional loops/sequences) which allow me to put values which are equivalent
to symbols into the array. The value are taken from eight diferent list. 

I enclose maple worksheet and screenshoot with explanation what I need.

I wil be appreciated for any help.

DA_-_help.mw

I have a new question here about using maple, welcome to answer

http://math.stackexchange.com/questions/1049655/how-to-calculate-a-in-this-description

Dear all, I have been trying to use Runge-Kutta method to plot an approximate solution with the following code. However, although I can get the numerical approximation the plot would not show.

h := .1;

x[0] := 0;

y[0] := 1;

xf := 3;

n := floor(xf/h)

f:= (x,y)->1/(3 y-x-2)

x := x[0]

y := y[0]

for i to n do

k1 := f(x, y);

k2 := f(x+(1/2)*h, y+(1/2)*h*k1);

k3 := f(x+(1/2)*h, y+(1/2)*h*k2);

k4 := f(x+h, h*k3+y);

k := (k1+2*k2+2*k3+k4)*(1/6);

y := h*k+y;

x := x+h

end do;

y[n]

data := [seq([x[n], y[n]], n = 0 .. 30)];

p[2] := plot(data, style = point, color = blue);

p[3] := plot(data, style = line, color = blue);
display(seq(p[n], n = 2 .. 3));

Does anyone in the community know example worksheets that analyze "billiards", viz. trajectory sets of free, specularly reflected particles constrained to bounce around in a particular 2d domain?

Are there any examples using the Bunimovich Stadium Billiard?

Thanks,

Bob Terry

declare(W(x, y), Z(x, y));

sys := [-A*kappa3-`&PartialD;`(`&PartialD;`(W(x, y))/`&PartialD;`(x))*(2*G-A)/`&PartialD;`(x)-2*G*(`&PartialD;`(`&PartialD;`(W(x, y))/`&PartialD;`(y))/`&PartialD;`(y)+`&PartialD;`(`&PartialD;`(Z(x, y))/`&PartialD;`(x))/`&PartialD;`(y))+A*`&PartialD;`(`&PartialD;`(Z(x, y))/`&PartialD;`(x))/`&PartialD;`(y) = 0, `&PartialD;`(`&PartialD;`(Z(x, y))/`&PartialD;`(y))*(A-4*G)/`&PartialD;`(y)+`&PartialD;`(`&PartialD;`(W(x, y))/`&PartialD;`(x))*(A-2*G)/`&PartialD;`(y)-2*G*`&PartialD;`(`&PartialD;`(Z(x, y))/`&PartialD;`(x))/`&PartialD;`(x) = 0];

I have this system of coupled PDE and I wish to solve it using Maple.

It gives me error of this kind:

pdsolve(sys, [[W(x, y)], [Z(x, y)]]);

Error, (in pdsolve/sys) found functions depending on different variables in the given DE system: [`&PartialD;`(x), `&PartialD;`(y)]

Thanks a lot for help

I don't know what mean is T and V0x?

Please.

Dear all,

I want to know how can I solve a fourth or higher order equation to find out its roots, actually coefficients of each power terms itself are functins of other parameters not constant.

Please reply as soon as possible, as this is very urgent,

Regards.

I noticed this in Student:-NumericalAnalysis:-Romberg, here are the lines of interest:

The question  is: Why create rtable, apply algorithm, then convert to Matrix at end? Why not replace line 4 below with Matrix command from start? Could not the same thing be done using Matrix from the start?

-----------------------------------------
proc(expr, var, a, b, n)
local f, R, j, k, i, oldDigits;
   4   R := rtable(1 .. n,1 .. n,('storage') = ('triangular')['lower']);  #Why not create Matrix here?
   6   R[1,1] := evalf(1/2*(b-a)*(f(a)+f(b)));
   7   for k from 2 to n do
   8     R[k,1] := 1/2*evalf(R[k-1,1]+(b-a)/(2^(k-2))*add(f(a+(2*i-1)*(b-a)/(2^(k-1))),i = 1 .. 2^(k-2)))
       end do;
  10   for j from 2 to n do
  11     for k from j to n do
  12       R[k,j] := evalf(4^(j-1)*R[k,j-1]-R[k-1,j-1])/(4^(j-1)-1)
         end do
       end do;
  13   R := evalf[oldDigits](R);
  14   return convert(R,Matrix,('shape') = ('triangular')['lower']) #Why not use Matrix from the start?
end proc
------------------------------------------

Maple 18.02

True of False, Explain:

If ∏/2<θ<∏, Then cos θ/2<0

As title , there has 2 balls(A and B) which I can change Quality 、Radius and Position for two dimensions(x and y axis),

A has a velocity and B quiescence , let A strike to B .

As shown below

I did a sample ,but i can't make it accurately .

test.mw

I want to let my sample like the below sample

http://www.mapleprimes.com/questions/202467-How-Does-Maple-Make-A-Rutherford-Scattering-

I noticed, when using

restart;
with(LibraryTools);
Browse();

That some procedures have lost all its formating. No line numbers, no spaces in between, very hard to read. For example, dsolve() in maple.mla is like this. While other procs are well formated and easy to read.

Is there a reason for this? And is there a way to fix this in Browse() to be able to read the source? It is impossible to read it like this readlly. Maple 18.02 on windows.

I have couple questions on displaying/printing items I see from ShowContents(LibLocation). Here is an example

restart;
with(LibraryTools):
LibLocation:=cat(kernelopts(mapledir),"/lib/maple.mla");
c:=ShowContents(LibLocation):

First quesionNow, when I do
c[1];
then I see

When is "%?.m" there? Is this suppoed to be an actual function one can print?

second question

c[30]; gives

But when I do:

interface(verboseproc=3);
print(AiryBiZeros);

I get listing that ends up calling

---------------------------
proc(n::{algebraic, algebraic .. algebraic})
local fn;
   1   if nargs <> 1 then
   2     error "wrong number of arguments"
       end if;
   3   fn := traperror(evalf(n));
   4   if type(fn,'numeric') and not type(n,'posint') or type(fn,('numeric') .. ('anything')) and not type(op(1,n),'posint') or type(fn,('anything') .. ('numeric')) and not type(op(2,n),'posint') then
   5     error "expecting positive integers in argument"
       elif type(n,('integer') .. ('integer')) and op(2,n) < op(1,n) then
   6     NULL
       else
   7     ('AiryBiZeros')(n)   <----- Is this C function/compiled that is why it does not show?
       end if
end proc
--------------------------------------

Which is the same name I printed. So it seems to be another internal procedure with same name? How can I print it as well?

Is there a better way to print Maple procedures/command than what I am doing above so one gets full listing?
I tried Browse(); command in LibraryTools, but found it very cluncky to use (keeps losing listing and screen become blank. Very buggy)