deqn4 := {4*eta^4*(diff(f(eta), eta, eta, eta))*(diff(f(eta), eta))-12*eta^3*(diff(f(eta), eta, eta, eta))*f(eta)+12*eta^4*(diff(f(eta), eta, eta))*(diff(f(eta), eta))-36*eta^3*(diff(f(eta), eta, eta))*f(eta)-24*eta^3*(diff(f(eta), eta))^2+12*eta^2*(diff(f(eta), eta))*f(eta)-36*eta*f(eta)^2-4*eta^3*(diff(f(eta), eta, eta))*(diff(f(eta), eta))-12*eta^2*(diff(f(eta), eta, eta))*f(eta)+12*eta^3*f(eta)*(diff(f(eta), eta))+36*eta^2*f(eta)^2-4*eta^3*(diff(f(eta), eta, eta, eta, eta))-12*eta^3*(diff(f(eta), eta, eta, eta))+12*eta^2*(diff(f(eta), eta, eta))-12*eta*(diff(f(eta), eta))+24*f(eta) = 0};
/
| 4 / d / d / d \\\ / d \
< 4 eta |----- |----- |----- f(eta)||| |----- f(eta)|
| \ deta \ deta \ deta /// \ deta /
\

3 / d / d / d \\\
- 12 eta |----- |----- |----- f(eta)||| f(eta)
\ deta \ deta \ deta ///

4 / d / d \\ / d \
+ 12 eta |----- |----- f(eta)|| |----- f(eta)|
\ deta \ deta // \ deta /

3 / d / d \\
- 36 eta |----- |----- f(eta)|| f(eta)
\ deta \ deta //

2
3 / d \ 2 / d \
- 24 eta |----- f(eta)| + 12 eta |----- f(eta)| f(eta)
\ deta / \ deta /

2
- 36 eta f(eta)

3 / d / d \\ / d \
- 4 eta |----- |----- f(eta)|| |----- f(eta)|
\ deta \ deta // \ deta /

2 / d / d \\
- 12 eta |----- |----- f(eta)|| f(eta)
\ deta \ deta //

3 / d \ 2 2
+ 12 eta f(eta) |----- f(eta)| + 36 eta f(eta)
\ deta /

3 / d / d / d / d \\\\
- 4 eta |----- |----- |----- |----- f(eta)||||
\ deta \ deta \ deta \ deta ////

3 / d / d / d \\\
- 12 eta |----- |----- |----- f(eta)|||
\ deta \ deta \ deta ///

2 / d / d \\ / d \
+ 12 eta |----- |----- f(eta)|| - 12 eta |----- f(eta)|
\ deta \ deta // \ deta /

\
|
+ 24 f(eta) = 0 >
|
/
init4 := { {f(0) = 1, (D(f))(0) = 0, ((D@@2)(f))(0) = 0, ((D@@3)(f))(0.1e-2) = 0} };
{{f(0) = 1, D(f)(0) = 0, @@(D, 2)(f)(0) = 0,

@@(D, 3)(f)(0.001) = 0}}
dsol4 := dsolve(deqn4 union init4, numeric, method=rkf45);

Error, (in dsolve/numeric/process_input) system must be entered as a set/list of expressions/equations

Hi,

I have a eight different size lists.

I want to put it into the Array with simplest and clear way as possible respect to first column and containg symbols.
I enclose workseet.

Could you help somone?.
Thank you in advanced

wzel

fill_the_array.mw

i find maple help using regular chain library, but it has ideal source and ideal target,

when compare with singular, seems different, i am not sure singular code whether correct or not.

so, would like to ask how to do this in maple

if you know singular, i would like to know too.

ring r = 32003, (x,y), lp;
setring r;
ideal Z;
ideal i = x-x2-2*x*y+2*x2*y-2*x*y2+y+y2, 1-x2-2*x*y+2*x2*y-2*x*y2+y2;
map phi = r, i;
ideal i1 = preimage(r,phi,Z);
i1;
ideal i2 = preimage(r,i,i);
i2;
ideal i3 = preimage(r,i,Z);
i3;
ideal i4 = preimage(r,Z,i);
i4;

would like to apply to find Cohen Maculay

While(NewKer <> 0)

Mapping = Basis(M – N) ^ K[M]

NewKer = ker(Mapping, M, N)

N = M

M = NewKer

If IsCM(NewKer) = true then

    NewKer

End if

Do

Dear All,

I need your help to plot the phase portrait using DEtools[DEplot]  these are the lines of the code. But when I make RUN, there is an error. I need your help to fix the error. Many thinks.

r1:=1; r2:=1; q2:=2; q1=0.5;  a1:=1;

Sys1 := {diff(N(t),t) = r1*N*(1-N/q1)-P*N/(1+N), diff(P(t),t) = r2*P*(exp(-a1*P)-q2)+P*N/(1+N)};

DEtools[DEplot](Sys1,[N(t),P(t)],t=-10..10,N=0..2,P=0..2);

Many thinks

Hello, Maple wizards.

I have a problem with Tasks for parallel computations. In each task my programm should execute this command:

>B:=SignalProcessing:-DFT(A)

"A" and "B" are Arrays (1..m). "m" is integer. I have 8 tasks. Each task is a loop ("for i from 1 to n do..." n is integer), where my command is executing. "A" and "B" are local for each task. In this case each task should execute my command n times.

So, I obtain this:

"Error, (in SignalProcessing:-Engine:-DFT) attempting to assign to `FwdDFT` which is protected"

What is it? In Maple Help I read that ">SignalProcessing:-DFT" is Thread-Safe Function.

I have a characteristic equation. some times It has polar roots . sometimes It has real roots and sometimes both of them.

I want to extract real roots and extract polar roots if they are.

for instance:

q:=m3*r^3+m2*r^2+m1*r+m0:

rot:=solve(q=0,r);

I want to know how can I use if in this part ?

Can maple solve maximization problem like

q := proc (a, b, c) options operator, arrow; .2*b+.1*c end proc;
print(`output redirected...`); # input placeholder
(a, b, c) -> 0.2 b + 0.1 c
w := proc (a, b, c) options operator, arrow; .7*a+.1*c end proc;
print(`output redirected...`); # input placeholder
(a, b, c) -> 0.7 ab + 0.1 c
e := proc (a, b, c) options operator, arrow; .7*a+.2*b*c end proc;
print(`output redirected...`); # input placeholder
(a, b, c) -> 0.7 a + 0.2 b c

with(Optimization)

Maxmize(int(min(100+(.7*a+q)*(1/2), a), q)+int(min(100+(.2*b+w)*(1/2), b), w)+int(min(100+(.1*c+e)*(1/2), c), e)-a-b-c-ab-ac-bc)

Error, (in Optimization:-NLPSolve) cannot convert procedures to piecewise

Thanks alot if you can help me.Urgent! Really appreciate.

Hi there,

I used the following plot command in maple13.

with(plots):

implicitplot(abs(x)+abs(y)=2, x=-2..2, y=-2..2, scaling=constrained)

But the output(square) is not complete at vertices.In fact at the vertex the graph is like a trapezoid.

Any help will be appreciated.

Yegan

> restart;
> with(plots);
> Eq1 := diff(f(eta), eta, eta, eta)+f(eta)*(diff(f(eta), eta, eta))-2*(diff(f(eta), eta))^2-M^2*(diff(f(eta), eta)) = 0;
/ d / d / d \\\ / d / d \\
|----- |----- |----- f(eta)||| + f(eta) |----- |----- f(eta)||
\ deta \ deta \ deta /// \ deta \ deta //

2
/ d \ 2 / d \
- 2 |----- f(eta)| - M |----- f(eta)| = 0
\ deta / \ deta /
> Eq2 := 1+(4/3)*R*(diff(theta(eta), eta, eta))+Pr*(f(eta)*(diff(theta(eta), eta))-(diff(f(eta), eta))*theta(eta)) = 0;
4 / d / d \\
1 + - R |----- |----- theta(eta)||
3 \ deta \ deta //

/ / d \ / d \ \
+ Pr |f(eta) |----- theta(eta)| - |----- f(eta)| theta(eta)| = 0
\ \ deta / \ deta / /
> bcs1 := f(0) = S, (D(f))(0) = 1+L*G, (D(D(f)))(0) = .1, f(6) = 0;
f(0) = S, D(f)(0) = 1 + L G, @@(D, 2)(f)(0) = 0.1, f(6) = 0
> fixedparameter := [S = .1, M = .1];
[S = 0.1, M = 0.1]
> Eq3 := eval(Eq1, fixedparameter);
/ d / d / d \\\ / d / d \\
|----- |----- |----- f(eta)||| + f(eta) |----- |----- f(eta)||
\ deta \ deta \ deta /// \ deta \ deta //

2
/ d \ / d \
- 2 |----- f(eta)| - 0.01 |----- f(eta)| = 0
\ deta / \ deta /
> fixedparameter := [R = .1, Pr = .7];
[R = 0.1, Pr = 0.7]
> Eq4 := eval(Eq2, fixedparameter);
/ d / d \\ / d \
1 + 0.1333333333 |----- |----- theta(eta)|| + 0.7 f(eta) |----- theta(eta)|
\ deta \ deta // \ deta /

/ d \
- 0.7 |----- f(eta)| theta(eta) = 0
\ deta /
> bcs2 := theta(0) = 1+T*B, (D(theta))(6) = B, theta(6) = 0;
theta(0) = 1 + T B, D(theta)(6) = B, theta(6) = 0

> T := .1; B := .1;
0.1
0.1
> L := [0., .1, .2, .3];
[0., 0.1, 0.2, 0.3]
> for k to 4 do R := dsolve(eval({Eq3, Eq4, bcs1, bcs2}, L = L[k]), [f(eta), theta(eta)], numeric, output = listprocedure); Y || k := rhs(R[2]); YL || k := rhs(R[3]) end do;
Error, (in dsolve/numeric/bvp/convertsys) too many boundary conditions: expected 6, got 7
> plot([YL || (1 .. 4)], 0 .. 6, 1 .. -.2, labels = [eta, diff(f(eta), eta)]);

Dear all;

I need your help to get all the solution of this nonlinear  system  with four parameters: r1, r2, q1, q2  assumed to be positives. Let the system:

the first equation is: r1*x*(1-x/q1)=x*y/(1+x)

the second equation: r2*y*(exp(-y)-q2)=-x*y/(1+x)

How can get the positive solution ( x, y) of the previous system.

Thank you for your help.

Consider the function

The above definition may result in four cases depening on r and x.

Can Maple calculate automatically all possible cases and the corresponding Maxima, Minima and Values at intervals limits?

I have an ode in the form:

diff(u(x),x)-f(x)=u(x)^3+B(X)*u(x)+g(x)

how to extaract and name the different coefficients of the equation?

Thanks 

Hamada

Having a little trouble getting data from openstreetmap from export here

http://www.openstreetmap.org/export#map=17/43.4763/-80.5459

The system :

I am trying to recreate journal work for validating using another computer program so I am trying to use maple to solve the ODE, based on further research I found using laplace might be the best but I am having some trouble.

eq8:=d*(n(t)+C(t))/drho = -rho(t)/(l*alpha*K_c)

given the initial conditions of:

ICs:= n(0) = n_0, rho(0) = rho_0, C(0) = (beta-rho_0)*n_0/(l*lambda)

therefore: 

equation9 := dsolve({equation8, ICs}, {C(t), n(t)}, method = laplace)

Following this process I get the error: 

Error, (in dsolve) invalid initial condition

According to the journal work the solution I am looking for is: 

C(t)=-n(t)+(rho_0^2+rho(t)^2)/(2*l*alpha*K_c)+((Beta+l*lambda-rho_0)*n_0)/(l*lambda)

is there something that I'm doing wrong or missing? 

Any help would be greatly Appreciated!