Hi,

  I have a file "d:\\test.txt", the content is 

       1, 2.0000 + 0. I

then I use

f:=readdata(`d:\\test.txt`,2);
for i from 1 to 1 do
print(i,f[i]);
end do:

it gives me

***

[[1.]]
1, [1.]

 ***

If I remove the comma in the file, I could obtain 2. I do not want to do it manually that remove all commas by hand. Is there any way to skip the commas in readdata?

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'm working on my master thesis and trying to solve this equation on maple, after I developed my equation and solving it for N=2,3 and then trying to solve it for N=4 and 5 it took so much long time(more than two days without get any answer), so i'm asking you now to help me reducing the time for solving this complicated equation. 

Shklovskii_N_spheres_with_tails.mw

Download Shklovskii_N_spheres_with_tails.mwShklovskii_N_spheres_with_tails.mw

I have two lists with differential monomials, like this: [y'y'', y''', (y'')^2].

List is rather big, i want to check if one such a list contains in other.

Seems to be that there is some internal procedure for this operation.

But I don't know what it is...

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

Dear friends:

If

n:=197

then

d:=convert(n,base,10) --> returns [7,9,1]

Is there a simple way for getting back n from d, i.e., 197 from [7,9,1] , not using a for loop?

Thanks and best regards

César Lozaada

Nm= p1.
p2 ...pm + 1, for m more than or equals 1.

So N1 = p1 + 1 = 2 + 1 = 3, N2 = p1 p2 + 1 = 2
3 + 1 = 7, etc.

We prove that Nm is not divisible by any of p1, p2, . . . , pm, so that Nm is either a prime or it is divisible by a prime larger than pm.

(c) Use Maple to find out which of these numbers Nm, for m = 1, 2, . . . , 15, is actually prime.

Use Maple to compare pm with the smallest prime number that divides Nm, for m =1, 2, . . . , 15.

So I am brand new to using Maple and am trying to solve a system of ODE's. When I try and use dsolve however I reciever the error "function expected" and I am not sure why. The code I have is as follows

sys_ode := diff(A(t), t) = a*(A(t)+B(t))-b1*A(t)*(C(t)+D(t))-g1*A(t)*B(t), diff(B(t), t) = -b2*B(t)*(C(t)+D(t))+g1*A(t)*B(t), diff(C(t), t) = e*(b1*A(t)+b2*B(t))*C(t)-g2*b2*C(t)*B(t)-g3*C(t)*D(t), diff(D(t), t) = g2*b2*C(t)*D(t)-m*D(t)

dsolve([sys_ode])

I'm sure it is something simple, but I just can't seem to figure out where the issue is. Any help is much appreciated.

I'm trying to substitute one Differential equation into another differential equation.

eq1:=d*n(t)/dt = (rho(t)-beta)*n(t)/Lambda+lambda*C(t)+q

eq2:=diff(eq1, t)

resulting in -> eq2 := d*(diff(n(t), t))/dt = (diff(rho(t), t))*n(t)/Lambda+(rho(t)-beta)*(diff(n(t), t))/Lambda+lambda*(diff(C(t), t))

then I'm given that (diff(C(t), t)) is given by another equation: 

eq3:=d*C(t)/dt = beta*n(t)/Lambda-lambda*C(t)

At this point I'm trying to substitute equation 3 into equation 2 for diff(C(t),t)

eq4 := subs(diff(C(t), t) = rhs(eq2), eq5)

however no matter what way's I try this I get an error: 

Error, (in simpl/reloprod) invalid terms in product: (d*(diff(n(t), t))/dt = (diff(rho(t), t))*n(t)/Lambda+(rho(t)-beta)*(diff(n(t), t))/Lambda+lambda*(diff(C(t), t)))^-1

I then tried to map it but again i got an error specifically about the first parameter: 

Error, invalid operator parameter name

eq5:=map((d/dt C(t))->beta/Lambda*n(t)-lambda*C(t),eq2)

I'm just wondering if what I am trying to do is even possible in Maple? 

If anyone can help I would greatly appreciate it! 

The system :

Hello ..

I need codes bifurcation and cobweb for logistic map by maple ..

can you help me ?

Thanks ...

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! 

I want to simulate Inelastic collision

There has 2 ball which I can change  Quality and Radius.

one ball  move to another stirless ball with diferent angle

Hi

I need your help .. I solve a system and I get the error Warning, solutions may have been lost.

The maple code is attached.

testerror.mw

Thank you for your help.