In preparation for learning GR, I need somme trick on how to use the DifferentialGEometry package or else. So I want to show you what I want to do (see the link to the document below) and I would like some help on how to do it with tensor.  That would help me a lot.  Then, I will extansion it on a 3-D problem and next in 4-D.

Thank you in advance dor your help

here is the file : Finding_covariant_and_contravariant.mw

--------------------------------------
Mario Lemelin

Maple 2015 Ubuntu 14.04 - 64 bits
Maple 2015 Win 10 -  64 bits
messagerie : mario.lemelin@cgocable.ca
téléphone :  (819) 376-0987

For the life of me I cannot find the method to do so.

So the solution would look like:

1. Euation

2 Step 2

3 Step 3

4 step 3+n

where n is the number of steps reuired.

Any help will be appreciated so very much.

.

.TIA

Larry C

Is there in Maple a command to verify that one segment on the real axis is a subset of another segment?  For example  RealRange(2, 4)  is subset of  RealRange(2, 5) . 

Of course easy to write a procedure that makes it:

Subset:=proc(r1::RealRange, r2::RealRange)

local a, b, c, d;

a, c:= op~(1,[r1, r2])[];

b, d:= op~(2,[r1, r2])[];

if a>=c and b<=d then true else false fi;

end proc:

Example of use:

Subset(RealRange(2,4), RealRange(2,5));

Subset(RealRange(2,5), RealRange(2,4));

                            true

                            false

I have this matrix

and I would like to evaluate the variables like this

I tried this

but it didnt work.

Any suggestions??

Thank you so much

I want to compute some matrix multiplications and i need this expression to be 1 always, i.e,

x^2+y^2+z^2+w^2=1

for every calculation I do.

I have tried x^2+y^2+z^2+w^2:=1 and assign(x^2+y^2+z^2+w^2,1) but it doesn't work.

What I should type to make it work?

Thank you

Hi,

In line with my previous questions

http://www.mapleprimes.com/questions/201944-Convergence-Problem-In-My-Algorithm-DSOLVE

I write a code with different variables and odes. However I tried to get the solution, I cannot get the results. I think it should be some problems with my Guess procedure. The code is attached. I would be most grateful if you help me on this problem.

code.mw

Thank you.

Amir

with(DynamicSystems)

T:= a vector

Iwant to make a single plot of:

DiscretePlot(T,x1,stile=stair); DisdretPlot(T,x2,stile=stair)

The usal way: DiscreePlot(T,[x1,x2]... ain't work

Thansk for helping

I am trying to solve a PDE which is converted to ODE when we assign one of the  variables some value. The boundary conditions given to the PDE are numerical values given for fixed numerical values to the two independent variables. I am trying to solve the PDE with the staandard syntax:

pds := pdsolve(pde,[ibc],numeric,time=z,range=0..beta);

The error message I get is:  

Error, (in pdsolve/numeric/process_PDEs) PDEs can only contain dependent variables with direct dependence on the independent variables of the problem, got {theta(z, 0)}

The pde and boundary conditions are as follows:

PDE:   pde := diff(theta(z, 0), z, z)+theta(z, 0)

Where zero is the fixed value for an independent variable

Boundary Condition:  ibc:={theta(0,0)=beta,D[1](theta)(0,0)=0};

When I try to solve it as an ODE the error is:

Error, (in dsolve) not an ODE system, please try pdsolve

Hello,

I would like to know : how I can get all the contents of the module GetMultibody of MapleSim?

Is there in classic maple a function enabling me to ask the content of a module ?

Thank a lot for your help.

Hello

i was stuck with some simple problem. I tried using if condition in program that involves a truth condition. If maple cannot determine the condition is true or false i want to assign o to a particular varable. I  show a similar program.

restart;

h[1] := -1;

for i from 1 by 1 while(i<150 and h[i]<0) do

p1[i] := .989347189582843*x^2-0.139423979061219e-1*x-1.82559474469870*10^8*x^15+1.30761381361453*10^8*x^16-6.88520063191821*10^7*x^17+2.51079317463498*10^7*x^18-5.66094206949155*10^6*x^19+5.94129446612678*10^5*x^20-6812.74182685426*x^5+59230.0931084044*x^6-3.83520584559500*10^5*x^7+1.90126822307036*10^6*x^8-7.34991883857609*10^6*x^9+2.24203561757434*10^7*x^10-5.43284775909785*10^7*x^11+1.04806113793011*10^8*x^12-1.60600324339222*10^8*x^13+1.94090536353833*10^8*x^14+559.557918804679*x^4-30.6576714427729*x^3-3.93727537464007*10^(-15)-i^2-i; fsolve(p1[i]-0.312e-1, x, -1 .. 1);

if fsolve(p1[i]-0.312e-1, x, -.2 .. 0) < 0 then h[i+1] := fsolve(p1[i]-0.312e-1, x, -.2 .. 0) elif FAIL then h[i+1] := 0 end if;

print(i, h[i])

end do;

i got an error message

Error, cannot determine if this expression is true or false: () < 0

how can i get a value of 0 for h[i] if the error comes.

Thanks.

Aditya

Hello,

I would like to change the numbering of my equation.

For the moment, the numbering of my equations is : 4.2.4 for Section 4, Subsection 2 and 4th equations.

I would like to keep the number for the section but to remove the numbers for the subsections.

Consequently, I would like to have this kind of result only : 4.4 for Section 4, Equation 4.

Do you have some ideas to do this changement ?

Thanks a lot for your help.

i have to compute lie algebra condition by using maple 15, but currently i have code in maple 5.,

i already try to run in maple 15 but it say 'error,unable to match delimeters'
i try to find error, but i cant find it..
the coding are here...

check[lie]:=proc(A,n)

local  i,j,k,l,m;  

for i from 1 by 1 to n do

for j from 1 by 1 to n do  

for k  from 1 by 1 to n do    

if A[i,i,k]<>0 then  

RETURN ('Input is NOT a Lie algebra (',i,i,k,')=',A[i,i,k], 'is not zero');  

elif A[i,j,k]+A[j,i,k]<>0 then  

RETURN ('Input is NOT a Lie algebra,(',i,j,k,')+(',j,i,k,')=',A[i,j,k]+A[j,i,k],'is not zero');  

else  

for 1 from 1 by 1 to n do

if  

simplify(sum(A[i,j,m]*A[m,l,k]+A[j,l,m]*A[m,i,k]+A[l,i,m]*A[m,j,k],   m=1..n))<>0  

then  

RETURN('Input is NOT a Lie algebra---the Jac(',i,j,l,') is not zero');    

fi;  

od;  

fi;  

od;  

od;  

od;  

print('Yes,input IS a Lie algebra');  

end:

can anyone help me here? Thank You..

Here, i attached the result in printscreen

Hi,

I ues the optimization tool in Maple2015.

In my experience, Maple optimizatiom tool just shows the optimum values, not a history of the optimizatiom process.

I want to know how I can obtain the history of the optimization process, such as values of the objective, constraints, and tolerance at every iteration.

Is there anyone who knows how to obtain the history data of the optimization process?

Do you have physical components like MOSFETs and IGBTs in your library? How can I have a look at the tool and library block sets?

Hi everyone,

I am trying to solve the equation of heat tranfer, time dependent, with particular Initial and boundary conditions but I am stuck by technical problems both in getting an analytical solution and a numerical one.

The equation

the equation.

I defined a and b numerically. domain is : and I defined surf_power numerically.

The initial condition is : , T0 defined numerically

The boundary condition is : , because it has a shperical symetry.

To me, it looks like a well posed problem. Does it look fine ?

Problem in analytical solution :

It doesn't accept the boundary condition so I only input the initial condition and it actually gives me back an expression that can be evaluated but it never does : I can't reduce it more than an expression of fourier which I can't eval. The solution :
The solution calculated in (0,0). I was hoping T0...

Are you familiar with these problems ? What would be the perfect syntax you would use to solve this ?

The numerical solution problems :

Sometimes it tells me that my boundary condition is equivalent  to 0 = 0, and I don't see why. Some other times it tells me I only gave 1 boundary/initial condition even if I wrote both. Here is what I wrote for example :

(because it kept asking me to add these two options : 'time' and 'range')

Are you familiar with these problems ? What would be the perfect syntax you would use to solve this ? I must at least have syntax problems because even if I keep reading the Help, it's been a long time since I used Maple.

Thank very much for any indication you could give me !

Simon