# Maple Questions and PostsMaple Questions and Posts Feed

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### need to procedure for calculating......

39 minutes ago
0 0

hi....how i can extract Coefficients  (i.e. {f1[2],f2[2],f2[3],f3[2],.....f3[6]}) from every algebric equations and create matrix A ,in form AX=0, (X are f1[2],f2[2],f2[3],f3[2],.....f3[6] ) then the determinant of the matrix of coefficients (A) set to zero for obtaining unknown parameter omega.?

Note that  if m=3 then 6 equations is appeare and if m=4 then 9 equations is appeare.thus i need a procedure that works for every arbitary value of ''m''.

in attached file below m=4 thus we have 9 equations, i.e. 3 for eq1[k_] and 3 for eq2[k_] and so on...

also we should use boundary conditions for some amount of fi[j] (i=1,2,3 and j=2,3,...,7)

be extacting above Coefficients for example from first equation ,

''**:= (1/128)*f1[2]*omega^2-(1/4)*f2[2]-(1/2)*f2[3]+(1/4)*f2[4]+(1/4)*f3[2]-(1/2)*f3[3]+(1/4)*f3[4]+140*f1[2]-80*f1[3]+20*f1[4]'''

must compute

coeff(**, f1[2]); coeff(**, f2[2]) and so on...

fdm-maple.mw

############################Define some parameters

############################Define some equation

######################################  APPLY BOUNDARY CONDITIONS

 (1)

### How can I install Maple on another pc?...

4 hours ago
2 2

Good morning, I'm a student and I installed Maple 18 on my PC, as a "Single User Profile". Unfortunately, I had to buy another computer, so now I'm trying to install the program on my new one. Even if I enter my Purchase Code and my details, Maple says that no more activations are left in my account, even if the expiration date is on March 2020. Is it possible to activate again the program?

Thank you,

Laura

### I just have a point of clarification about evalua...

5 hours ago
2 5

Hi everybody,

I would like to understand why the instruction

seq(X__k, k=1..2)

returns

Xk, Xk

and not X1, X2 ?

Is it possible to force the evaluation of X__k each time k changes in the "seq" loop ?

### Annoying Array() display problem...

8 hours ago
0 2

It seems as if arrays can only be displayed in 2-D form when the array dimensions start at 1.

Sometimes I want to construct arrays where an index starts from 0 (or other values). This is purely for my convenience in some problems. However such arrays do not display in 2-D form. Consider the displayed form of

Array(1..4,1..5,(i,j)->i+j);

Array(1..4,0..4,(i,j)->i+j);

Why doesn't the latter 'display' in 2-D form?

### Factorization of expression ...

17 hours ago
1 12

Hello people in Mapleprimes,

I want to factor

g^((2*(-sigma+k+1))/(-1+sigma))-tau^2

as

(g^((-sigma+k+1)/(-1+sigma)) -tau)*(g^((-sigma+k+1)/(-1+sigma))+tau);

I know that the following code works:

subs(g^((2*(-sigma+k+1))/(-1+sigma))=(g^((-sigma+k+1)/(-1+sigma)))^2,g^((2*(-sigma+k+1))/(-1+sigma))-tau^2);

factor(%);

Isn't there another better way than this?

taro

### How do I filter a set?...

18 hours ago
1 2

Dear Colleagues,

I am not sure if there exist a simple way to handle the issues I am facing. I am trying to obtain numeric roots for a polynomial f(x,a). I know for sure that there can be many roots depending on the value of parameter a. However, I cannot say for sure how many roots are possible for each value of parameter a. Some of these roots are complex numbers. Also, I need to choose only those roots that have following properties:

1. They are real.

2. f(x*,a) i.e., function value at a root is positive.

How do I solve f(x,a)=0 to store all roots in a set? Furthermore, how do I select and print roots that have the properties mentioned above? Is there a way to do filtering of a set specifying properties of the members of the set? Please suggest. Your help is highly appreciated.

Regards,

Omkar

18 hours ago
0 0

### Define a lie group with complex and real variables...

Yesterday at 9:32 AM
1 0

I am a beginer in Maple, and even more beginner with differential geometry on maple. I am trying two dayes now to define the following Lie group on Maple by reading the help guid of DifferentialGeometry and some documents on the web, but I failed. Now I am seeking for your assistance, Plese help me and thanks for being as xplicite as you can.

The group I want to introduce is the real lie group

$\mathbb R \times \mathbb C$ () equipped with the group law
$$(x_0,x) \cdot (y_0,y) = (x_0+y_0+\frac{1}{2}Im(x\bar{y}), x+y)$$

(I didn't figure out how to use something other than LaTeX code)

illustration purpose I am sticking with the above simple example, but I want next to move to higher dimensions analog.
I want also an explication about how Maple distinguishes between a real and complex coordinate.

I want next to compute  the left multiplication pushforward of a tangent vector of the identity.
Then compute the structure constants of the Lie algebra associated. Then compute the structure constants of the Lie algebra associated. I think Maple can do this kind of manipulation without problem, am I wrong?

### Defining a quantum operator as a tensor – And limi...

Yesterday at 7:52 AM Maple 2016
2
2

Hi,

In the following example I introduce some commutation rules that are standard in Quantum Mechanics. A major feature of the Maple Physics Package, is that it is possible to define tensors as Quantum Operators. This is of great interest because powerful tensor simplification rules can then be used in Quantum Mechanics. For an example, see the commutation rules of the components of the angular momentum operator in ?Physics,Examples. Here, I focus on a possible issue: when destroying all quantum operators, the pre-defined commutation rules still apply, which should not be the case. As shown in the post, this is link to the fact that these operators are also tensors.

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 (1)

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First, set a 3D Euclidian space

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Define two rank 1 tensors

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Now, further define these tensors as quantum operators and gives the usual commutation rule between position and momentum operators (Quantum Mechanics).

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 (4)

As expected:

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 (5)

Now, reset all the Hermitian operators, so that all quantum operators are destroyed. This is useful if, for instance, one needs to compare some the result with the commutative case.

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 (6)

As expected, there are no quantum operators anymore...

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 (7)

...so that the following expressions should commute (result should be true)

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 (8)

Result should be 0

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 (9)
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 (10)
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Below is just a copy & paste of the above section. The only difference, is that "" has been commented, so that and  are not a tensor. In that case, everything behaves as expected (but of course, the interesting feature of tensors is not available).

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First, set a 3D Euclidian space

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 (11)

#Define two rank 1 tensors

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Now, further define these tensors as quantum operators and gives the usual commutation rule between position and momentum operators (Quantum Mechanics)

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 (12)

As expected:

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 (13)

Now, reset all the Hermitian operators, so that all quantum operators are destroyed.

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 (14)

As expected, there are no quantum operators anymore...

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 (15)

...so that the following expressions should commute (result should be true)

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 (16)

Result should be 0

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 (17)
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 (18)
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### Error, (in pdsolve/numeric/process_PDEs) can only ...

Yesterday at 1:15 AM
0 6

hi .may every one help me for pdsolve this differential equations?

all initial boundary condition are zero

thanks...

pdeSol_(1).mw

 > # # Define some parameters #   sigma := 10; N := 0; beta := 1; alpha := 1; PDE1 := diff(w(X, theta, t), X, X, X, X)+2*alpha^2*(diff(w(X, theta, t), theta, theta, X, X))+alpha^4*(diff(w(X, theta, t), theta, theta, theta, theta))-N*(diff(w(X, theta, t), X, X))+diff(w(X, theta, t), t, t)-beta*w(X, theta, t)-sigma = 0
 (1)
 > # # Define the PDES #   PDEs:= { diff(w(X, theta, t), X, X, X, X)+2*alpha^2*(diff(w(X, theta, t), theta, theta, X, X))+alpha^4*(diff(w(X, theta, t), theta, theta, theta, theta))-N*(diff(w(X, theta, t), X, X))+diff(w(X, theta, t), t, t)-beta*w(X, theta, t)-sigma = 0    };
 (2)
 > # # Set of boundary conditions at x=1. #    bcs1:= { D[1](w)(1,theta, t) = 0,               w(1,theta, t) = 0          };
 (3)
 > # # Set of boundary conditions at x=0 #   bcs2:= {    w(0,theta, t)=0,            D[1](w)(0,theta, t)=0          };
 (4)
 > # # Set of boundary conditions at t=0 #   bcs3:= { w(x,theta,0)=0,                       D[2](w)(x,theta,0)=0 };
 (5)
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 > pdsolve( PDEs, union(bcs1, bcs2, bcs3), numeric);
 >

### HELP WITH MAPLE 2016 PROGRAM...

Yesterday at 6:29 PM
3 2

Hello everybody, I'm an engineer student and I'm having quite some troubles with Maple. See my teacher told us to program a homework using Maple, problem is I've never used Maple in my life and it's not that hard, but I'm having some trouble with my homework.

My homework is about a 4-bar mechanism (grashof's condition) which will define the type of movement my mechanism will have depending on the data I input:

we define 4 variables expressed lenght measurments:

L= (largest link in the mechanism)
S= (smallest link in the mechanism)

P and Q= other 2 links in the 4 bar mechanism

also

L0: the link of the mechanism which is FIXED (frame)

L1: the link of the mechanism which is moves (driver)

here 1 will be the fram, 2 the driver, 3 the coupler and 4 the follower

grashofs condition consist on the following:

1. IF L + S < P + Q

and S is the frame, then the program should print that the mechanism presents a rotatory-rotatory movement

or L+S < P+Q and the FRAME is the opposite link of the shortest link, then the program should print that the mechanism presents oscilatory-oscilatory movement

or L+S<P+Q and S is the driver and the frame is adyacent to the driver, then the program should print that the mechanism presents two rotatory movement.

2. IF   L + S > P + Q

the program should print that the mechanism doesn't follow grashof condition and the movement is roker-rocker (doesnt matter what link is the driver and what link is the frame)

3. IF L+S=P+Q

the program should print that the mechanism doesn't follow grashof condition and the mechanism will have deadpoints.

I'm sorry, im a mechanical engineer student and I have very few experience programming (I only learned python like 2 years ago) and I'm having trouble with maple's language (which i know is very simple)

If someone could help me or guide me I would really appreciate it

Thanks alot

PD. excuse my english

### How do I save a matrix in an intermediate step of ...

Yesterday at 5:22 PM
1 10

I am working on an iterative code where I need to save a matrix in an intermediate step. My code is long and it uses a separate data file. So, I am trying to state my problem taking a simple example.

At first, I define a column matrix A0. Using A0, I do some calculations and test some conditions.
In the next step, I want  to do similar calculations and test some conditions but this time by changing the first element of A0. For the purpose of later use, I need to save the matrix A0 in its original form. I am trying to use the following method but both A0 and A1 (modified A0) turn out to be same.

> restart;
> n := 3;
> A0 := Matrix(n, 1, 1);
> #Do some calculation with A0
> A1 := A0;
> A1[1, 1] := A1[1, 1]+.1*A1[1, 1];
> A1;
> print(A0, A1);

This might be because I set A1:=A0 in the third line. But how do I save A0 in its original form?

### numerical equation using loop for...

August 23 2016
0 2

hello evrey one ,

my question is how can i solve numerical equation using loop

for each beta => deolve and export via excel
thank you

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August 23 2016
1 5

 > restart:
 > P:=w-10*z-1/5*z^2-1/200*z^3-1/500*z^4-z^5-1/1000*z^6
 (1)
 > solve(P,z)
 (2)
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