Hi,

I'm trying to solve the following differential equation numerically with dsolve:

but dsolve gives me this error:

> res := dsolve(DGL, numeric, parameters = [y0, A, B, C, E]);
Error, (in DEtools/convertsys) unable to convert to an explicit first-order system

I think the problem is that I use the wrong solver. Does Maple provide a solver which is capable of solving this kind of equations (nonlinear ODE)?

Thanks in advance!

hello , to solve a differential euqations , maple gave me this error. please help me.

TG.mw

Hello, 

I`m new with the Physics package. I have a Hamiltonian in a lattice written in terms of creation and annihilation operators. The Question is, How can I label a Creation and an Annihiliation operator for each site in the Lattice. WIth this, I can compute mean values and other stuffs associated with the Hamiltonian.

Many thanks in advance

Hi,

  Excuse me, I tried to substract in a series expansion. It works for Taylor-type expansion, but not Laurent-type ones

*********

ffff:=1/(t-3);
ggg:=taylor(ffff,t=infinity,3);
coeff(ggg,t,-1);

ffff:=exp(t);
ggg:=taylor(ffff,t=0,3);
coeff(ggg,t,1);

*********

Maple gives me

Error, unable to compute coeff

1

. My question is, why "coeff" does not work in the first case? how to make it work? Though I can copy the expansion part, assign it to another variable, and "coeff" will work

Excuse me,

  I have the following input

***

fff:=x1^k;
int(fff,x1=0..x2);

***

I would like to obtain

1/(k+1)* (x2^(k+1)), k<>-1

but maple gives me just the same integral. Is there any way to get the expression?

Thank you!

I am trying to make a plot3d on my Surface Pro  3 running Windows8.1.

The plot looks like a ghost.  Pale grey.  It looked nice and colourful when I executed the same command on an older computer a few hours ago.  (I know it was exactly the same command because I saved the file on my old computer and then opened in on the Surface Pro 3)

Is there a way to fix this?

plot3d(-x^2+y^2-3*x+2*y+100, x = -5 .. 8, y = -5 .. 5, transparency = 0, lightmodel = light1, glossiness = 1, filled = true, style = wireframeopaque, shading = zhue, view = [-5 .. 10, -5 .. 8, 0 .. 150]);

 OOPS!  Now the problem has corrected itself.  

I'm getting worried about all the weird things Maple is doing on this Surface Pro 3.  I'm trying to make up a final exam tonight (the exam is tomorrow).

I have downloaded MaplePlayer on my iPad.   I see that it comes with a number of "pre-recorded" programs that it can run.  Is there a way to have it run a Maple worksheet that I have written?   If so, how do I use this app to open an existing worksheet? 

Also, are there any plans for this app on the Android platform any time soon?

I have written a program and I would like to embed a check near the beginning to see if input data was entered correctly.  I have written an "if statement" to check on this and I would like the program to stop execution at this point if the "if statement" criteria are met.   I get an error saying that this command is disabled.   I have tried "stop", "end" and "quit," as I understand that they are all the same.

TwoEquations.mw

Download TwoEquations.mw

Hi all,

I have a simple transfer function like

I want to calculate the amplitude ratio and the phase shift.

Without maple I would set s=I*omega and solve for real and imaginary part to obtain the phase shift and amplitude ratio.

Is there any possibility to do that in Maple more easily?

Hi,

When I run a maple program which take a long time (in command line), I have this kind of message every second:

"memory used=43867.3MB, alloc=147.3MB, time=856.28"

Does there exist any way to avoid this display ?

Thanks in advance.

How would one in Maple solve this, which is an inequality equation in some variables, which can be nonlinear, with constraints on range of each variable. I.e. I want to find conditions on the variables to make the inequality satisfied.

In Mathematica, I use the Reduce command

Clear[x, y];
eq = 1/2 - x + x^2 - y + y^2;
Reduce[{eq > 0, 0 < x < 1 && 0 < y < 1}, {x, y}, Reals]

How would one do the same in Maple? I tried solve, but can't give constraints.

restart;
eq:=1/2 -x+x^2-y+y^2:
solve(eq>0 , {x1, x2});

So I need to do the same as in the Mathematica command, but in Maple. I do not want numerical solution, but algebraic as shown above.

Using Maple 18.2 on windows.

Hello people in mapleprimes,

I want to ask a question about modification of expression.

Basically, what I want to do is to change the expression of sqrt((-a)^2) to sqrt(a^2).

The expression I want to modify is this:

aa:=phi[n, j] = a[j, D]-a-sqrt((-a[j, D]+a+tau[n, j])^2+4*gamma*f[c, n, j]/L[j])

I want to change this to 

phi[n, j] = a[j, D]-a-sqrt((a[j, D]-a-tau[n, j])^2+4*gamma*f[c, n, j]/L[j])

To do this, I wrote as 

subs(sqrt((-a[j, D]+a+tau[n, j])^2+4*gamma*f[c, n, j]/L[j]) = sqrt((a[j, D]-a-tau[n, j])^2+4*gamma*f[c, n, j]/L[j]), phi[n, j] = a[j, D]-a-((-a[j, D]+a+tau[n, j])^2+4*gamma*f[c, n, j]/L[j])^(1/2))

Or, I wrote as 

subs(op([2,3,2,1,1],aa)=(a[j, D]-a-tau[n, j])^2,aa)

If there is better ways, please tell me them.

Best wishes.

taro

I would be grateful if anyone would comment on the compatibility of Maple 18 and MacOS 10.10 (Yosemite).

A 37 foot ladder is placed against a wall that is 9 feet away from its base. Will the top of the ladder reach a window ledge that is 35 feet above ground? Explain.