Dear,

I'm trying to reproduce in Maple an integer linear programming example from Chvatal's book: 

Maximize z= 4x₁ + 5x₂ + 5x₃ + 2x₄

Subject to 33x₁ + 49x₂ +51x₃ + 22x₄ <= 120,  x_i = nonnegative integers. 

The optimal solution is: x₁ = 2,   x₂ = 1,  x₃ = x₄ = 0,     z=  13.

In Maple I type: 

 LPSolve( 4x₁ + 5x₂ + 5x₃ + 2x₄, {33x₁ + 49x₂ +51x₃ + 22x₄ <= 120}, maximize, assume ={nonnegative, integer}); 

but Maple gives me back the following error: 

Warning, problem appears to be unbounded. [0, [x₁ =0, x₂ =0, x₃ =0, x₄ =0]]

I know the example has the abovementioned definite solution since it comes from the textbook. So, what could I be doing wrongly? 

Many thanks for your help. 

As useful as the SetProperty and GetProperty commands are in this package, I am seeking a command that is called by the action of a user input prompt, for example, the prompt window question is something like:

"How many parameters of silly do you want to specifiy for this analysis? (maximum is 10)"

And once the user has entered a natural number between 1 and 10, that number of components of a specified type is generated  in the worksheet.

Is this a real thing already and I can't find it or is there a round about way to do it without an actual command existing?

Hi good afternoon , im looking for maple code of HPM to solve time dependent diffusion reaction , can anybody help me . I didnt get how to solve it by maple . 

I am fairly new to programming i Maple. I am trying to constuct a package which takes two list xlist, ylist, and using the imported Fit commands from the statictics package, tries to do line fitting. 

What am I missing to get this to work? :) 

Mat:=module()
    description "My Package";
    option package;
    Statistics(Fit);
    export LinModel; 
    LinModel :=proc(xliste::list, yliste::list,x::algebraic, $)
        return Fit(xliste,yliste,x)
        end proc; # LinModel 

    end module; #Mat

Does anybody know the inverse of x^5 + 2x^3 ???

Let A be an nxn matrix over Z, the ring of integer numbers. Let m be a positive integer number.

My question: Is there a method in Maple such that we obtain the inverse of A in modulo m.

I know that if m be a prime number then the command "Inverse(A) mod m" returns the desired result. But how about the situation when m is not a prime number.

Thanks for any Help

I'm new to Maple, and i'm learnning Maple with basic commands(the version I use is Maple2019). But after I entered some commands, the results Maple gives me is not what I expected. For example:

When i enter abs(3+5*I), I hope get a $\sqrt{34}$, but Maple gives me a complex number:

abs(3 + 5*I);
                                                         -58                                                     -59  
       1.81847767202745 10    + 7.53238114626421 10    I
sin(0);
                                                        -116                                                    -116  
      2.73949338633639 10     + 2.73949338633639 10     I
sin(pi);
                                                        -116                                                    -116  
      2.73949338633639 10     + 2.73949338633639 10     I
abs(3 + 5*I);
                                                        -58                                                      -59  
       1.81847767202745 10    + 7.53238114626421 10    I

expand(cos(4*x) + 4*cos(2*x) + 3, trig);
                                                                          -231  
                 8. - 3.75241200689042 10     I
Why???

Should I set or define something or what?

Thank you!

Hello! 

I have been using maple not so long ago and I can’t always understand for myself what is the reason for the program not working.
In this case, I need to solve a system of second-order differential equations with respect to four variables. I don’t understand what’s wrong, do not judge strictly.

// 
restart;

m1 := 50;
m2 := 70;
R1 := 0.14;
R2 := 0.17;
O1C1 := 0.3;
alpha := 0.024;
a := 0.28;
b := 0.08;
c := 0.08;
M0 := 12;
k1 := 1.7;
k2 := 0.9;
Zb := -a;
Md := M0 - k1*diff(varphi(t), t);
Mc := -k1*diff(varphi(t), t)^2;

Ixz := 0;
Iyz := m1*O1C1*(b + c) + m2*R2^2/4*alpha;
Izz := m1(R1^2/2 + O1C1^2) + m2*R2^2/4*(alpha^2 + 2);

eqMx := -M*Yc*diff(varphi(t), t $ 2) - M*Xc*diff(varphi(t), t)^2 = Xa + Xb;
eqMy := M*Xc*diff(varphi(t), t $ 2) - M*Yc*diff(varphi(t), t)^2 = Ya + Yb;
eqIy := -Ixz*diff(varphi(t), t $ 2) + Iyz*diff(varphi(t), t)^2 = Zb*Yb;
eqIx := -Iyz*diff(varphi(t), t $ 2) - Ixz*diff(varphi(t), t)^2 = Zb*Xb;
eqMz := Izz*diff(varphi(t), t $ 2) = Md + Mc;
sys := {eqIx, eqIy, eqMx, eqMy};
dsolve({sys, varphi(0) = 0}, Xa, Xb, Ya, Yb);

Error, (in dsolve) invalid arguments; expected an equation, or a set or list of them, received: { and so on }

//

I will be glad if you help me with this problem. if there are certain questions, you - ask, and I'll answer.
Here you can find the file: Курсовой_по_термеху_2.mw

I have an ordinary differential equation to be solved. when I give numeric values to B,H and L__1 (for example B=10,H=10,L__1=4), everything works fine and equations eq37a will be solved.

but when B,H and L__1 are symbolic parameters, dsolve give me this error " Error, (in dsolve) give the main variable as a second argument". and I don't know what it means.

is there any way to solve the ODE with symbolic B,H and L__1??

Download Mechrect.mw

I use transition matrix guess the next note of Happy birthday, but it tends to the same note in the final few notes

what is wrong?

why?

restart;
with(LinearAlgebra):
with(AudioTools):

MK := proc(f::numeric)
AudioTools:-Create(duration=0.5,rate=44100,x->evalhf(sin(x*2*Pi*f/44100))):
end proc:

C4 := 261.62:
D4 := 293.67:
E4 := 329.63:
F4 := 349.23:
G4 := 392.00:
A4 := 440.00:
B4 := 493.88:
C5 := 523.25:

initstate := Matrix([[0,0,0,0,0,0,0],[0,0,0,0,0,0,0],[0,0,3,2,0,1,1],[0,0,2,0,0,0,0],[0,0,1,0,0,0,0],[0,0,1,0,1,0,0],[0,0,0,0,0,1,0]]);
statetemp := []:
for i from 1 to op(1,initstate)[1] do
if add(x, x in initstate[i]) = 0 then
statetemp := [op(statetemp), [0,0,0,0,0,0,0]]
else
statetemp := [op(statetemp), initstate[i]/add(x, x in initstate[i])]
end if:
od:
state := Matrix(7,7);
for i from 1 to op(1,initstate)[1] do
for j from 1 to op(1,initstate)[2] do
state(i,j) := statetemp[i][j];
od;
od;
state := MatrixMatrixMultiply(state, state);
member(max(state[3]),state,'pos');
member(max(state),state,'pos');
pos;
music := [A4,B4,C4,D4,E4,F4,G4];
song := [C4,C4,D4,C4,F4,E4,C4,C4,D4,C4,G4,F4,C4,C4]:
song := [op(song), music[pos[1]]];
for i from 1 to 10 do
state := MatrixMatrixMultiply(state, state);
member(max(state[pos[2]]),state,'pos');
member(max(state),state,'pos');
song := [op(song), music[pos[1]]];
od:
HappyBirthday:=Create(Vector(map(MK,song))):
Write("C:\\Users\\secret\\Documents\\HappyBirthday.wav",HappyBirthday);
 

Hello

I know that anames( 'user' ) recovers the contents of the workspace but I wonder whether it would be possible to recover only the contents of each m-file read within a worksheet.  

Many thanks

Ed

Dear All,

I have the following differential equation:

(diff(lambda(t), t) = lambda(t)*(rho - A*beta*h^(1 - beta + a)/(A*h^(1 - beta + a)*t*(1 - beta) + k^(1 - beta))))     (1)

where rho, A, beta, a, h and k, are known parameters. Note, that all of them are positive and parameters rho, beta and a are less than one.

When solving this equation by dsolve, I get:

lambda(t) = _C1*exp(rho*t)*(A*h^(1 - beta + a)*t*beta - A*h^(1 - beta + a)*t - k^(1 - beta))^(beta/(-1 + beta))    (2)

which when substituting, for instance, beta=0.3 into the obtained solution, transforms into:

lambda(t) = _C1*exp(rho*t)/(-0.7*A*h^(0.7 + a)*t - k^0.7)^0.4285714286                                                                (3)

However, if I already have put beta=0.3 into the original differntial equation (see (1)) and solve it, I receive:

lambda(t) = _C1*exp(rho*t)/(10*k^(7/10) + 7*A*h^(7/10 + a)*t)^(3/7)                                                                       (4)

Clearly, the resultant solutions in (3) and (4) are quite different since the solution of (3) is any complex number and in (4) it is a real number. Note, that when solving the differential function (1) numerically, there exists a solution for any value of beta.

I also have tried to rename beta (supposing that maybe beta is any protected name) but the result remains the same. Also note, that if such manipulation is done with any other parameters, the solutions (3) and (4) are the same.

I will be thankful for any clarification regarding this issue. 

Thanks in advance,

Dmitry

My maplet

mpt := Maplet(Window("Точка выше или ниже прямой",
[[Plotter[f]()], ["1st vector"],
[TextField[v1](), TextField[v2](), TextField[v5]()],
["2nd vector"],
[TextField[v3](), TextField[v4](), TextField[v6]()], ["Скаляр"],
[TextField[scalar]()], [Button("Add", Evaluate(f = 'work(1)'))],
[[ToggleButton['d2']("2D", 'value' = true, 'group' = 'BG1')],
[ToggleButton['d3']("3D", 'value' = false, 'group' = 'BG1')]]]),
ButtonGroup['BG1']())

Now I choose via toogle button what to plot 2D or 3D addition but I need to plot it in two different plotter, is there a way to do it?

Procedure 

with(Maplets);
with(Elements);
with(Tools);
[AddAttribute, AddContent, Get, ListBoxSplit, Parse, Print, Set, 

  SetTimeout, StartEngine, StopEngine]
with(plots);
with(LinearAlgebra);
with(Student[LinearAlgebra]);

with(Maplets[Elements]);

work:=proc(g)

     local x1, y1, x2, y2, scalar;z1, z2,d2,d3,u,v,U,V,r1,r2,r3,R1,R2,R3,V1:
 x1 := Get(v1::algebraic);
 y1 := Get(v2::algebraic);  

z1 := Get(v5::algebraic);  

x2 := Get(v3::algebraic);  

y2 := Get(v4::algebraic);  

z2 := Get(v6::algebraic);  

scalar := Get(scalar::algebraic);

 d2:= Get(d2);  

d3:= Get(d3);    

 if d2 = true then  u, v:=<x1, y1>, <x2, y2>;  

elif d3 = true then   u, v:=<x1, y1,z1>, <x2, y2,z2>;  

end if;  U:=arrow(u, color=red):  

V:=arrow(u, v, color=black):    

   r1:=u+v: r2:=u-v: r3:=ScalarMultiply(u,scalar):r4:=ScalarMultiply(v,scalar):  

R1:=arrow(r1, color=red):

 R2:=arrow(v, r2, color=black):  

R3:=arrow(r3, color=black):

 R4:=arrow(r4, color=black):  

V1:=arrow(v, color=blue):    

if g = 1 then return VectorSumPlot(u,v, show=1, caption="Треугольник", vectorcolors=[red,blue]);    

end if;  

end proc:

Repeat once again what do I need: I want to plot addition of vectors in 2D and 3D in 2 different plotters at once

https://www.maplesoft.com/applications/view.aspx?SID=3938&view=html

i find this example

how to write piano note A and B frequency music to wave file?