I got the eigenvalues of the Jacobian matrix of a nonlinear time variant system. One of them is like:
0.5000000000e-2-0.2500000000e-2*y+0.5000000000e-2*x+0.2500000000e-2*sqrt(36.-12.*y-24.*x+y^2-4.*x*y+4.*x^2)
Now I'd like to make x and y still vary with time, i.e.
0.5000000000e-2-0.2500000000e-2*y(t)+0.5000000000e-2*x(t)+0.2500000000e-2*sqrt(36.-12.*y-24.*x(t)+y(t)^2-4.*x(t)*y(t)+4.*x(t)^2)
x(t) and y(t) bear a relation by differential equations.
Any ideas on how I implement this?
Thanks a lot!

Hi
I have been trying to extract the data from an eigenvectors() command to an Excel file.
I have tried some basic writedata() commands but without luck. I´m guessing that the "strange" format of the output from the eigenvectors() command:
[eigenvalue1, algebraicmultiplicator, [eigenvector1]], [eigenvalue2, algebraicmultiplicator, [eigenvector2]],
and so forth
is what is causing the problem.
Does anyone know how I can do this?? Would mean alot to me if anyone does since it is eigenvalues and eigenvectors from an 31x31 matrix....ehhm :)
Best regards
Einar

I wonder if someone could help me with the following situation. I copied the procedure 'differentiate' shown on p62 of the MAPLE10 Aadvanced Programming Manual. When I fed this proc w/ the parameters 2 - x + x^2 + 3*x^9,x as indicated on pg. 63 I did not get the result shown in the book.

View 2292_P62 AdvancedProgrammingGuide.mw on MapleNet or

Download 2292_P62 AdvancedProgrammingGuide.mw
Hi
I am not quite sure why the variable,(Tw) is not plotted. It is dependent on all the variables evaluated in the ode calculations but yet the wall temperature, Tw, is not evaluated.
Anyone could tell me why?
Thanks a lot
Elinor

View 3860_extent of reaction (COKE).mw on MapleNet or

Download 3860_extent of reaction (COKE).mwView file
Hi everyone,
Could you please have a look at my maple file. Im trying to solve a set of 4 differential equations but maple takes ages to solve and doesnot give the answer at the end either. The reason can be that the equations have to high power.
Do you know any other dsolve method I can use or anything I can do to fix this problem?
Thank you very much!
Jinny

View 3868_Pressure drop 2.mw on MapleNet or

Download
Hi, I created a scatter plot in a Maple 11 Worksheet by creating a list (below) and right clicking and using the Plot tools.
However, I want to graph a function on the same scatter plot. Can this be done?
L := [[32, 6], [48, 14], [64, 24], [80, 38], [96, 55], [112, 75]]

Is there a package available in Maple that converts between number systems ?
e.g., binary, octal, hexadecimal.
v/r,

Thanks to all the wonderful and timely help I received concerning my previous troubles with the LegendreP function.
It was all helpful.
I think I'm very bad at procedures, but I struggled in an effort to gain more personal knowledge, in addition to solving this problem and came up with a very simple and rudimentary procedure.
It is called P[legend](l,m), where l and m are the two arguments received in that order.
Can anyone look at this procedure and suggest improvements for efficiency, aesthetics (more elegant simpler methods), possible bugs, etc.
Your critiques on my effort would be greatly appreciated.

Somewhere along the line, my output format switched to display the most significant digit in the tenths decimal place. I can't figure out how to change it back to the unit (one's) decimal place. Anybody know where to find this setting?
Thanks,
Brad

None of these suggestions allow for the evaluation of the directional derivative at a particular point, in this case (1, -2, 3). (I cannot make the command line suggestion work at all - error: "expects its 2nd argument, v, to be of type ('Vector')(algebraic), but received [x, y, z]")
Surely, evaluation can be done without an additional substitution statement.
John Vawter

Hello
I have a very strange math question and I want to verify the result with MAPLE but I really have no idea why (we have no "Maple" notes with our course yet)...
I want to find the gradient of exp(x*y*z)*cos(x*y^3*z^2) and exp(x*y)*cos(x*y^3*z^2) at point (0,0,0) with direction 2i-3j+k.
It seems like a very strange question, the gradient at (0,0,0) of both functions seem to give 0. I don't really care about the direction, if only I could verify the gradient at (0,0,0), it would be great.
Thx

Hey, I'm trying to make a density plot for the hydrogen wave functions in maple
I only see how to make a density plot in cartesian coordinates,
but I want to make a density plot in polar or better in 3D spherical coordinates.

I am trying to get the directional derivative for a 3 variable (x,y,z) function. Maple is saying:
Error, (in Student:-MultivariateCalculus:-DirectionalDerivative) include points for only the x and y coordinates
for entry
DirectionalDerivative(x*exp(y)/(3*z^2+1), ([x, y, z]) = ([2, -1, 0]), [1, -2, 3])
Any help would be greatly appreciated.
Thanks,
Dave

Does anyone know how to get the function

LegendreP(1,1,cos(theta)) to return the value of sin(theta) ?

I'm using the associated Legendre function.

I think the first 1 represents the degree of the polynomial, and the second 1 stands for the derivative order. (I'm not sure).

When using the associated Legendre function, LegendreP(u,v,cos(theta)), I get the expected results only for certain combinations of the values of u and v.

The problem has to do with the eveness and oddness of u and v.

I also tried manipulating the global variable, _Env...? (Can't recall it's full name).