Unanswered Questions

This page lists MaplePrimes questions that have not yet received an answer

I am trying to solve the following function for 'r' and 'theta' at various values of 'a' and 'zeta' in order to detemine the saddle points (r,theta). I have tried the following and it works fine! However, the process takes quite a long time. I was wondering if there is another method...say Newtons Method or otherwise to go about solving the two simultaneous equations (eq1,eq2) for (r,theta)?

Thanks

Robert

a:=1: zeta:=1:

I have a physics problem that I hope to get help from this forum. The question is like this:

 I have figure here but I cannot paste it. Anyway I will try to make an explanation of where the points in the circle are located.

 

I have 103 tables ( aal_l,  abf_l  etc )  which each has columns D, T, O, H, C  etc 

I want to exctract column C for all 103 table and store the result in a matrix

 

I know how to extract column C for one table

 

convert(connection:-ExecuteQuery("select C from aal_l", 'output' = Array), Matrix)

 

but how can it be done for multiple tables ...?

Hi,

in Maple 12 (worksheet mode), the box Maple draws around a plot to allow the user to resize the plot using the mouse appears in all my plots far too big if I label the axis. Before labelling the axes, the box has the appropriate size, but as soon as I label the axis, the box becomes far too big resulting in my plot being very small while the bos goes from one end of the screen to the other.

Any help on that?

Thank you very much in advance,

Ben

 

I loaded a 1600*3 matrix into Maple 12  from my mysql datbase on my computer and it took 3 minutes to load it .

I assume that the speed will be increase significantly if I had a fast internet connection ( both up and down ).

My Internet connection (tcp / ip) is extremly slow !!    Is this correct ?   Are there any other way to speed up the data exchange ?

 

Hi,

I am a relatively new user of Maple, and I try to solve numerically the following PDE system :

> pde01 := diff(c(z, t), t) = (diff(c(z, t), z, z))-(diff(c(z, t), z))+k*(a-c(z, t));

> pde02 := diff(b(z, t), t) = (diff(b(z, t), z, z))-(diff(b(z, t), z))+k*(a-b(z, t));

> cl1 := c(0, t) = piecewise(t <= 0.3, 100, 0.3 < t and t <=0 .5, 200, 0.5 < t, 100);

> cl2 := c(l, t) = b(l, t);

> cl3 := (D[1](c))(l, t) = (D[1](b))(l, t);

> cl4 := b(L, t) = a;

Hi can someone please help me . My program gives me the correct solution but it crashes afterwards. Can anyone tell me whats wrong with the program please.

 

Hello, I am currently using Nelder Mead for an optimization problem. I used the following code taken out of the Maple Library (www.maplesoft.com/applications/app_center_view.aspx?CID=1&SCID=18&AID=1198) Concerning this code I have 2 questions: 1. The optimized values I get are sometimes negative. My solution should be limited on positive optimization values. I am not sure how to implement this. 2. The optimization is running quite slowly. Any suggestions how to improve the running time? Here are the most important parts of the code:

graph the surface, tangent line and normal line for:

xy + yz + xz = 3 (1,1,1). choose the domain so that avoid the extraneous vertical planes.

the paraboloid  z = 6-x-x^2 -2y^2 intersects the plane x=1 in a parabola. graph the paraboloid, the parabola and the tangent line at point (1,2,-4). any help.

Can someone explain how to do this?

Prove that if we describe the circle of center (a; b) and radius r using
the parameters (a; b; k), with k = a2+b2-r2, rather than the more natural parameters
(a; b; r), then the error function H(a; b; k) = E(a, b,rad(a^2 + b^2 -k) is quadratic in a; b
and k. What does this imply about the number of critical points?

#30

llvll=3              u=<4,-4>

-Find the magnitude of the given vector and divide each of the components by that magnitude. That will produce a unit vector that is the same direction of the given vector. Since it wants the magnitude to be equal to 3, multiply each component by 3. Make sure the radicans are out of the denominator. The answer should be a vector in component form.

 

#48

llvll=3            u=3i+4j

<p>I live in Los Angeles near UCLA and was wondering if there are Maple users in the neighborhood of Los Angeles who would be interested in forming some sort of local Maple Users group.  I would appreciate hearing from possible members,</p>

I got a big problem with one kind of integral function. Now, I am using Maple 8 or Maple 11 to get some results from my research topic. However, when I took three times integral like :

f:= Int(exp(-t^2),t = 0 .. infinity)+Int(Int(2*Int(.1*exp(-.25*(u-s-k)^2)*exp(-(-.5*u-.5*s-.5*k+t)^2)*exp(.25*(u-s-k)^2)*exp(-.1*k),k = 0 .. u-s)*exp(-u^2)*u,u = s .. t),t = 0 .. infinity);

After that, I try to draw the grahp of the above equation.

plot(f,s=0..1);

Hi everybody.

 

I'm using Maple these days to generate C code. More precisely, I use Maple to calculate high order derivatives. For example, I know that :

dt( u(x,t) ) = a(x) * dx( u(x,t) ) + b(x) * dx( p(x,t) )

dt( p(x,t) ) = c(x) * dx( p(x,t) ) + d(x) * dx( u(x,t) )

and I ask Maple to calculate the 5th time-derivative of u using these 2 properties. But in fact, I use 8 variables instead of 2 and PDEs are far more complicated.

Finally, I get thanks to Maple expressions of time-derivatives for my 8 variables.

 

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