I an experimenting with Groebner basis. Have a set 17 equations. There are 12 unknowns. Using 14 of the equations and tdeg, the system produced 65 equations. How do I get a list of the monomials in this new list?

how to do optimization for two equations in terms of two variables

LPSolve({eq1}, {eq2}, assume = {nonnegative});

eq1 is a rational function and eq2 is a very large rational function

after run , it return error, objective function must be specified as a linear polynomial or vector

da := [LengthSplit(Flatten([[1,m],[2,m2],[seq([i+1,close3[i][1]], i=2..4)]]),2)];
f := PolynomialInterpolation(da, z):
solution := solve(f=-z, z, explicit);
zz := [x1,x2,x3,x4];
sigma := symMonomial(zz); #sigma := [x1+x2+x3+x4, x1*x2+x1*x3+x1*x4+x2*x3+x2*x4+x3*x4, x1*x2*x3+x1*x2*x4+x1*x3*x4+x2*x3*x4, x1*x2*x3*x4]
sys1 := subs([x1=solution[1],x2=solution[2],x3=solution[3],x4=solution[4]], sigma[1]):
sys2 := subs([x1=solution[1],x2=solution[2],x3=solution[3],x4=solution[4]], sigma[2]):
sys3 := subs([x1=solution[1],x2=solution[2],x3=solution[3],x4=solution[4]], sigma[3]):
sys4 := subs([x1=solution[1],x2=solution[2],x3=solution[3],x4=solution[4]], sigma[4]):
da := [seq([i,close3[i][1]], i=1..5)];

with(Optimization):
LPSolve(sys1, {sys2}, assume = {nonnegative});

Hello all,

I have an ODE system (please see bellow) where my unknowns are S(t) and K(t), all the the other symbols are known parameters. This system, by given the initial values for S and K, that is, S(0)=100 and K(0)=20, I can solve numerically.

sys:= diff(S(t), t) = -eta*K(t)*S(t)/(w*N*(S(t)+K(t))), diff(K(t), t) = eta*K(t)*S(t)/(w*N*(S(t)+K(t)))+S(t)*(-z*eta*alpha*K(t)^2+(-z*eta*alpha*S(t)-(eta*alpha^2*S(t)^2-2*N*C[max]*w*eta*alpha*K(t)+((-N*w+z)*alpha+N*C[max]^2*w*eta)*w*N)*upsilon)*K(t)+N*S(t)*w*alpha*upsilon*(N*w-z))/((K(t)^2*alpha*z+3*K(t)*S(t)*alpha*z+(2*S(t)*z*alpha+upsilon)*S(t))*w*N)

In addition, I have an algebraic equation:

eq1:= -c2 + (K(t2)*S(t2)+w*N*S(t2))*z=0,

where S(t2) and K(t2) are the solutions of my ODE sys in S and K at t=t2. The t2 is unknown time variable. 

My question is: how can I find t2 such that my algebraic equation (eq1) is satisfied.

Thanks in advance,

Dmitry

Hi all,

I would like to plot a function U(x,t) in an interval [-2,0] such that

U(x,t)=u0(z)+t*u1(z) where  z=x/t,

u0(z)=z^2/3+sqrt(-z) and

diff(u1(z), z)=9/4*(84*(-z)^(11/2)-8*z^7+540*(-z)^(5/2)+324*z^4-324*z)*u1(z)/((z^2+3*sqrt(-z))*(2*(-z)^(3/2)+3)*(8*z^6+66*(-z)^(9/2)-189*z^3+216*(-z)^(3/2)+81))

I used numeric method rkf45 to solve and plot u1(z) with initial condition u1(-2)=1.

I can also use dchange to change variable z to x as variable and t as parameter.

But, I have difficullty to go back to U(x,t).

If someone have any idea.

Thanks in advance.

how to further remove _Z with explicit in two variables case?

da := [[1,m],[2,m2],[3,1],[4,2],[5,3],[6,4]];
f := PolynomialInterpolation(da, z):
solution := solve(f=-z, z, explicit);

Assume we have a sreach with 10 for, for example

answer=0:

for i[1] from 1 by 1 to 5 do

    for i[2] from 1 by 1 to 5 do 

        ...

        if .... then answer=1: print(i[1],...,i[10]); "quitting the search"

        ...

     end do

end do

If I write break at qutting part, it will only exit from one for, one idea is putting if answer=1 break before end do of the rest for, that is why I used the local extra variable "answer" but is this the best idea? Any better idea which contains checking less if is apprecied.

Tengo una figura obtenida con ScatterPlot3D a partir de una Matriz de 3 dimensiones ( X,Y,Z ). ¿ Cómo puedo obtener la función polinómica z(x,y) que reprenta la superficie que se obtiene en el ScatterPlot3D ?

Is there a library to draw state machine diagram from logic table in Maple?

Hello,

I am trying to plot 3d scattered data as a 2d scatterplot with the third dimension being displayed as colour or a line that separates the value of the two functions (for example, the higher value and lower value at that point). I attached the file. I have two functions and several parameters that are constant. Here, I want to use P[A] on the x-axis, and P[B] on the y-axis. The z dimension is the profit functions, either Profit[1] or Profit [2]. I want to show them in colors like the highest one is red and the lower one is green, or something similar.  P[A] and P[B] are probability values and P[B] is between 0 to 0.50 with 0.01 increments, while P[A] is always less than P[B]. The file is here: example_file.mw

Example;

P[A] := 0 ..P[B]-0.01

P[B] := 0 ..0.50

Anyone please help me to code this problem.Thanks,

YC

Hey

I have a simple question. 

In maple - when working with Ohm's Law.

Maple know how to calculate with e, but how can I show the result

I have calculated the following calculation:

(2e-4)/2

Maple returns the result:0.0001000000000

How do I maple show the result as 1e-4?

Download stefan.mw

Hello all,

I am pretty new to Maple, but I am trying to understand something. I was able to find a numerical solution to a PDE in maple (with some community help, thanks guys!). I am trying to manipulate this data but am struggling with it. I thought if I could take this data to matlab it would be pretty easy for me to manipulate and do what I want. 

So my question is: How do I export my numerical solution (pds module) to matlab. Just taking the data is okay. I know you can evaluate the data at some points. 

I see there is "Matlab" command that converts code, it doesn't seem to like pds as an input though.

I also see an export matrix command. I guess it could be possible to create a matrix of plot data and convert it this way?

I had to do a change of coordinate system to solve the PDE because of boundary conditions. I'm trying to transform this data back to my regular x,y coordinate system to see if it matches some other simulations. 

Thanks in advance! And here is my file.

restart;
with(Physics):
Setup(mathematicalnotation = true):

V(Z, f);

If function ( varphi) is defined, use this one.

PDE1 := subs[inplace](x = xi*varphi(t), PDE1);
If function ( varphi) is defined, use this one.


PDE1 := subs[inplace](t = 2*vartheta*(1/omega), PDE1);

Thesis_Pde2_attempt.mw

Consider the following two test procedures for creation of the same module:

createModule1 := proc(dim::posint)
    module()
        export det;
        det := (x::Matrix(1..dim,1..dim)) -> Determinant(x);
    end module
end proc:

and

createModule2 := proc(A::Matrix(square))
    local dim;
    dim := RowDimension(A);
    module()
        export det;
        det := (x::Matrix(1..dim,1..dim)) -> Determinant(x);
    end module
end proc:

as well as the following code lines calling these:

createModule1(       2 ):-det(IdentityMatrix(2));
createModule2(Matrix(2)):-det(IdentityMatrix(2));

The first line executes unproblematically, while for the second line an error results concerning the dimensionality check 1..dim,1..dim of the matrix. Why is dim available/initialized in the first version, while not in the second?

 from galois group function's result?