Unanswered Questions

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


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?


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.



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.


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.


Hi can anyone help me with this error please.

I don't knw wot it means or how to solve it:

Error, (in fprintf) integer expected for integer format

I gt the error for this line of code:

printf("No Roots Between The Interval %d \n",[a,b]);

I got an expression f:=R^3/(z^2+R^2)^(3/2); and would like to plot f as a function of (z/R), not z. Here R is a parameter. Could someone give me a hand?

Hi, I'm traying to maje a double integrate of P(A(t+Deltat),A(t)) , the first one in in untion of dA(t) and the second one is in fuction of dA(t+ DeltaT). How can I indicate in Maple Deltat?  Is it possible to integrate in function of A(t)?

All variables are constant, except A(t) and A(t + Deltat),

> F:=proc()

generally the function having zero points or poles with non-integer order such as f(z) = (z-a)^(1.5+i0.3) must be dealt with on appropriate Riemann surface. In the following link I tried to extend the argument principle for such functions on a single sheet of Riemann surface and got a formula similar to that of ordinary argument principle. Using that formula the winding number of f(z) = (z-a)^(1.5+i0.3) around the origin is expressed as 1.5+i0.3.

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