Mytest:=module()
    option package;
    
    export
        mymain
        ;
        
        
    # local a,b,c;

    uses LinearAlgebra;
    
    interface(rtablesize=infinity);
    
    
    mymain:=proc(n::integer)

        local ans;
        
        ans:=Vector(n);

        return ans;

    end proc;

end module;

Here is a short piece of code to create a Maple package. It runs fine. Is that possible to hide the code from print() ?

with(Mytest);

print(mymain); # which displays the source code

Could I hide some of the code? Say I want to use the function mymain() for debugging purpose, but I dont want to make it local to the package. Instead I keep it in "export", but I dont want users to see its code.

Thanks!

Hello I am a Maple 15 user and I am using the command fsolve to solve for the intersection of two curves over a specified interval in x, namely from 0 to the lim defined in the Maple document. The specified interval contains asymptotes and when I specify the full interval only one of the three solutions is returned even if I can see that there are three distinct solutions by looking at the plot of RHS and LHS. Should I use another technique to find the solution or is my implementation of fsolve command wrong?

Thanks in advance

Download HW4Q2.mw

Hey guys,

i'd like to create a custom component for maplesim. I opened the template in maple18 and defined the following equations:

eq := [p(t) = p__0+rho*g*h(t), Q(t) = A*(diff(h(t), t)), L(t) = 100*h(t)/h(0)]

These equations describes a tank with a liquid in it. Now I tried to define a function L(t) (above) that gives the level of the tank in percentage. Therefore I need the initial height value at t=0. The function defined above (h(0)) does not work, cause maple tells me that the function does not exist.

Any hint how to get an initial value or a value at t=0? Or maybe another way to solve my problem?

Hopefully I described right. :-)

Best regards

Christian

I am numerically solving a nonlinear system of nine equations. How long can I expect it to take?

I have run it for 30 minutes and it has not solved yet.

Here is the system of equations:

0=Lambda-mu.*S-beta.*(H+C+C1+C2).*(S./N)-tau.*(T+C).*(S./N);

0=tau.*(T+C).*(S./N)-beta.*(H+C+C1+C2).*(T./N)-(mu+mu_T).*T;

0=beta.*(H+C+C1+C2).*(S./N)-tau.*(T+C).*(H./N)-(mu+mu_A).*H;

0=beta.*(H+C+C1+C2).*(T./N)+tau.*(T+C).*(H./N)-(mu+psi.*mu_A+mu_T+lambda_T).*C;

0=lambda_T.*C-(mu+mu_A+rho_1+eta_1).*C1;

0=rho_1.*C1-(mu+mu_A+rho_2+eta_2).*C2;

0=eta_1.*C1-(mu+rho_1+gamma).*CT1;

0=eta_2.*C2-(mu+rho_2+gamma.*(rho_1)./(rho_1+rho_2)).*CT2+(rho_1).*CT1;

0 = N - S - T - H - C - C1 - C2 - CT1 - CT2;

and I have numeric values for Lambda, beta, tau, mu, mu_T, mu_A, rho_1, rho_2, psi, gamma. The only parameters left are eta_1, eta_2.

Thank you.

Hi everyone.

I wrote simple program with several functions. I would like to obtain parallel computing of my functions. I can't understand how to use nodes.

My programm.

Simple_example.mw

I'm trying to solve a series of equations and then graph them. I'm trying to solve for the variables involved:

values := solve({eq1, eq2, eq3, eq4, eq5, eq6, eq7, eq8, eq9,

eq10, eq11, eq12, eq13, eq14, eq15, eq16}, {a, b, b, c, d, e, f,

g, h, i, j, k, l, m, n, o, p});

. . . but it gives me this:

Warning, solving for expressions other than names or functions is not recommended. 

values := 

A major-league pitcher releases a ball at a point 6 feet above the ground and 58 feet from home plate at a speed of 100 mi/hr ,  

If gravity had no effect, the ball would travel along a line and cross home plate 4 feet off the ground. Find the drop D caused by gravity.                                                                                                                                                      

NB: in this problem the angle alpha is the angle between the horizontal and the direction of the released ball. Since the ball is dropping, alpha will be negative.

Let N be an integer. 

For each pair of integers (n,m) where 1<= n,m <= N, we have a variable f_{n,m}(t). 

Then for these we have a system of ODEs 

d/dt f_{n,m}(t) = \sum_{n', m'} f_m'n' * f_m''n'' * (m'n'' - m''n') 

where m''=m-m', n''=n=n', and the sum is simply over for all pairs (n',m'). 

I simply do not know how to put these set of equations into Maple in a nice way. 

I will really appreciate any help!

Hello,
Maple does not cancel out a variable.

Why is that?

Is there a way to solve this? 

(I pasted my code on the bottom of this message)

Thanks for your help/advice,

Stephan

restart:
M(x):=piecewise(x<=l,1/2*(q*x^2)/(EI)-3/8*(q*l*x)/(EI),l<x,1/2*(q*x^2)/(EI)-13/8*(q*l*x)/(EI)+5/4*(q*l^2)/(EI)):
M(x):=M(x)*(-EI);
# simplify() does not work.....?
M(x):=simplify(%) assuming EI>0;
# Wiht EI cancelled out by hand it schould look like:
M(x):=piecewise(x<=l,1/2*(q*x^2)-3/8*(q*l*x),l<x,1/2*(q*x^2)-13/8*(q*l*x)+5/4*(q*l^2));

Hi!

Please find my Maple-worksheet attached below.

How do I solve this problem? I can not drawn it.

I would really appriciate if somebody could help me. 

Hi!

I am quite new to Maple and have a problem I've been struggling with all day.

I have a spring pendulum and have to develop the equation of motion in the y-direction. The pendulum consist of a mass at the end of a elastic, unbendable and massless rod. 

Please find my Maple-worksheet attached below.

How do I solve the differential equation 2.9 for y(t)? As far as I can see the problem is that I have to differentiate y(t), which is not designated as a function, with respect to y (?)

I would really appriciate if somebody could help me. 

Thank you in advance!

Hi!

I am new to Maple and have a problem I've been struggling with all day.

I have a pendulum and need to find a equation of motion in the y-direction. Please find my code in the picture below.

I can see that my problem starts at Eqy where the differentiation deletes one of the right-hand-side parts because I don't have any function y(t), and Maple thinks y(t) a constant (?)
Can somebody please tell me what I'm doing wrong?

Thank you in advance!

This is my code for the Extended Euclidean Algorthim which should return integer l, polynomials pi,ri,si,ti for 0<=i<=l+1. And polynomial qi for 1<=i<=l such that si(f)+ti(g) = ri and sl(f)+tl(g)=rl=GCD(f,g).
The problem is, I keep getting division by zero. Also it evaluates pi = lcoeff(ri-1 - qiri) to be zero, everytime. Even when I remove this it still says there is a division of zero, which must be coming from qi:=quo(ri-1,ri, x); however I do not know why considering the requirements for the loop are that r[i] not equal zero. I really could use a fresh pair of eyes to see what I've done wrong. Any help would be greatly appreciated!!

Hi there,

Is there a way in which i can solve the following optimal control problem numerically with Maple?

 dH/dt=λ-µ H-(1-u1)β H V+δ I,

dI/dt=(1-u1)β H V-σ I,

‎dV/dt=(1-u2)k I-γ‎V,

dλ1/dt=-1+λ1µ+β‎‎V(1-u1)(λ1-λ2),‎

dλ2/dt=λ1δ+λ2σ-λ3(1-u2)k‎,‎

‎dλ3/dt=β H(λ1-λ2)(1-u1)‎‎+λ3γ.

where

u1=βHV(λ1-λ2)/A1,

u2=-λ3kI/A2,

σ = α + δ,

and

H(0)=1.7*10^8,    I(0)=0,    V(0)=400.

λ=5*10^5,    µ=0.003,     β=4*10^(-10),    α=0.043,    δ= 0.2                  k=6.24,       γ‎=0.65.

A1=900, A2=1000.

Answers and advice are very appreciated. 

Thank you all for reading.

Aylin

I got a problem with a difficult ode,the commands are below.

restart;
sys := 1.*(diff(x(t), t, t)) = piecewise(b(t) = 1, 0, 1003.0-1000.*x(t)-30.*(diff(x(t), t))-25.*signum(diff(x(t), t)-.1)-.3*signum(diff(x(t), t))*exp(-2*abs(diff(x(t), t)))), x(0) = 1, (D(x))(0) = 0;
mu := 100;
stick := [diff(x(t), t) = .1, b(t) = piecewise((1000.-1000.*x(t))^2 < 10000, 1, 0)];
slip := [[0, 10000 < (1000.-1000.*x(t))^2], b(t) = 0];
sol:=dsolve({sys,b(0)=0},numeric,discrete_variables=[b(t)::float],events=[stick,slip],event_maxiter=1000000,output=listprocedure,maxfun=0,range=0..8);

any advice is appreciated.