numeric_de.mw

hello boffins

if my de was soluble analytically, I would get an expression of time in terms of the other variables (V,theta,x) easily, but because it is only numerically solvable, i get an expression x(t)=proc(t)...,- the variables V and theta are mixed up in it-. Is there anyway they can appear?

I know I can put numerical values on V and Theta (and x) and solve for time (using parameters...

Hi all,

Is there a quicker way to find all unknows from an expression?

unknowns.mw

Say I want a list contains ALL parameters. In this case, it would return

[w1,w2,mu,tau[2],tan[3],tan[4],eta[1],eta[2]]

Is there a way to do this?

Thanks!

Casper

test.mw

Here is the problem, I will try my best to describe it:

Firstly of all,

log(p[j,c]/(1-p[j,c]))=mu+tau[j]+eta[c];

In this system, the 'j' is a time varying parameter, and the...

restart:with(LinearAlgebra):with(ArrayTools):k:=4;pA:=<seq(p[a,i],i=2..(k+1))>;pB:=<seq(p[b,i],i=2..(k+1))>;pA+pB;with(VectorCalculus):pA:=<seq(p[a,i],i=2..(k+1))>;pB:=<seq(p[b,i],i=2..(k+1))>;pA+pB;

After I loaded the package with(VectorCalculus), the output of vectors changed to a different one.

Is there any real "difference" when...

Please help me plot the graphs of the following equations:-

eq1 := diff(E[X(t)], t) = lambda-delta*E[X(t)]-beta*E[X(t)*V(t)];

eq2 := diff(E[Y(t)], t) = -delta*E[Y(t)]+beta*exp(-rho*tau)*E[X(t)*V(t)]; eq3 := diff(E[V(t)], t) = gamma+N*kappa*E[Y(t)]-mu*E[V(t)]-beta*E[X(t)*V(t)]

NB:- E[X(t)]= the expected value of variable X at time t.

Please help me know how to input this...

I have a differential equation having a parameter say 'a'.

If I increase 'a' by 10%, got change in the solution as well.

How to calculate change in percentage in the solution?.

Thanks

Hi,

So I've got a numerical solution to a D.E. and want to find which parameters (v, theta) cause the second event to occur. Here's my dsolve

> soln:= dsolve({eqx, eqy, inty, intx, x(0)=0, y(0)=0}, {x(t), y(t)}, numeric, method = rkf45, output=listprocedure, parameters=[v, theta], events=[ [ [diff(y(t),t)=0, y(t)

The first event is "Does the trajectory reach its max at a height less than 3.05m? If so, stop computation"...

Dear Maple users

Please help me correct this input:

> f := (c[A], c[B]) -> c[A]+c[B];Error, invalid operator parameter name f Assign Typesetting:-mambiguous( (c[A]comma c[B]) rarr c[A] + c[B], Typesetting:-merror(invalid operator parameter name))>

In Maple, c[A] is actually "c subscript A".

Thanks for help.

PS: Is...

I have a system consisting of a multi-body system and various modelica/maple custom components. The problem is whenever I re-run the simulation even though all the simulation settings are same, the simulation results are inconsistent. There should be no difference between each simulation as all the parameters/settings are same. I am attaching two pictures which are both obtained from two successive simulations

Dear MaplePrimes,

I have a problem findning an explicit solution to an equation solve((P[h]-tau[h])*q[hf] = (P[f]-tau[f])*q[fh], [lambda[h]])]. Is you can see from my syntax, I have assumed a RealDomain and also that all parameters including the varialbe I'm solving for lambda[h] are positive, and also that lambda[h] is between 0 and 1. This is my syntax:

test := `assuming`([RealDomain:-solve((P[h]-tau[h])*q[hf] = (P[f]-tau[f...

(1) Does ModuleCopy, when automatically called from Object, really get the a shallow copy of the object

as the first parameter in its parameter list? See below, which is copied directly from ?object,create. The

ModuleCopy has first argument new::Dollar but ModuleApply only passes its two arguments not three. I

couldn't find a reference to this feature in the docs.

Hello,

I am working on a physics problem that involves a bead on roating hoop. You need to use Lagrangians to solve this problem but this is not where i am strugling. My school expects us to use maple because it is the program the provide but none of the teachers know how to usem it (they use mathmatica) so they cant help us. We have the equation: θ"= [ω^{2}*cos(θ)-(g/R)]sin(θ) and the initial cond. θ'(0)=0 and θ(0)=θ

What do these parameters of Clutch mean,phi_nominal,w_small,k_locked?

And, how can I use them?

Anyone can tell me the detail?

Thank you.

Hello everyone.

I have 2 systems of differential equations which depend on variables from each other, of course the differential variable for each is different.

Not to get into the details of the system, since they are rather large, the problem is as follows:

I've managed to get with the parameters option a solution for x(z), in essence x(parameters=[a,b])(z). I've managed in turn to generate a procedure that would give me the avg value of x (xm...

The following simple code

myproc1:=proc({parlist::list:=[]}) return parlist[1]; end proc: myproc2:=proc(parlist::list) return myproc1('parlist'=parlist); end proc: myproc2([1,2]);

fails with

Error, (in myproc1) invalid subscript selector

The reason is that myproc1 has the optional argument parlist, which has the same name as myproc2. myproc2 seems to make...

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