Hello, I´m trying to create a maplets, but crash out with problem, I don´t now how to create in a smart way a method for count the number of varibles, I did that in the following lines: for Num from 1 to 1E6 do > A[Num]:=assigned(u[Num]): > if A[Num]=true then > N:=Num > end if; > end do: u[k] is a vector, and N, obviously the number of them. because I guess that the user, don´t want introduce more than a million of vectors, I don´t like that way. If somebody know the answer to my (maybe silly) question, please, explain it. Please replace this text with the link to your file.

I am trying to write a procedure which takes a list of (linear) expressions in two variables and a list of assumptions on the two variables and returns all of the possible orderings of those expressions. To my dismay, the assuming facility does not seem to be working properly. I using Maple 9 on a Windows System. The following input illustrates the problem. coulditbe(mU > 1-u) assuming mU true Maple returns true! The first assumption alone eliminates the possibility of this being true. What's going wrong and how do I get this to work? If you wish, you can plot these assumptions and though at least two are redundant, there is a feasible region.

Hello, I need to find relative extrema of an expression with inequalities. e.g. extrema(xi^2-x1^2-x2^2-xp^2-y^2,{xi-x1-x2+xp^2<=y^2},y); extrema command is not able to compute with inequalities constraints. Could you help me please? Thank you. Vladimir

Hi I am looking for eigenvectors of a messy jacobian matrix, maple is taking its sweet time with this (but still probably faster than me ;)) I have access to a 250 node(dual and quad opteron) cluster, is there anyway to run maple in parallel? If not will maple see a speed up when run on a dual proc or dual core workstation?

Hi I have the following command: > LinearSolve(E0,Z,free=R) assuming real; when I execute this I get: Error, (in assuming) when calling 'LinearAlgebra:-LinearSolve'. Received: 'unexpected argument(s): free = R, LinearAlgebra:-LinearSolve' I am not sure why? can anyone explain? Without free=R it works fine...

I have used Maple 7 under Windows 2000. Now I want to port it to Windows Vista. It seems to work well, but only when instructions are introduced onto the Maple screen by drag and drop from an external text file. When I try to type numbers or literals nothing appears on the screen. This peculiar behaviour is not observed with other programs, Mathematica (4.2), for example. Additionally, when I try to save a file, the Maple screen disappears immediately. There must be a simple solution of these problems, but I have not yet found it. Any help will be welcome. Thanks! Willy

It appears that Maple uses N as the denominator and not N-1 in calculating a covariance matrix in the Statistics package. Why? Harry Garst

To read data from file and fit it to a known equation,for example y a*x+b I used the commands: fs := ImportMatrix("C:\\Fit\\test.dat"): with(Statistics):eq:=Fit(BesselK(a*x+b,fs[1....200,1],fs[1...200,2],x); but I do not know how to let Maple calclate the values of y for each x after I knew the parameters a and b from the fitting.and how I can plot the fitting equation to compare it with the plot of the data to know is the fitting is good or know.

I want to find the real part of the following expression, but I keep having difficulty: simplify(evalc((zks/(alphas+I*vs)*(exp(-I*times*vs)-exp(-I*times1*vs-alphas*tds))))) assuming real; Maple refused to do it... what can I do? Thanks!

Maple folks, I am a Maple newbie. I am trying to figure out how to graph an inequality: x + y

Hi all, I am just playing around with Maple, with curiosity, to see how smart it is and how much can I rely on it for work... Here is a probably difficult integral, I couldn't get Maple to do it: assume(b>0, T>0, a>0, w>0); int(exp(-b*sqrt(w))/sqrt(a^2+w^2), w = T .. infinity); Is there a way to get it work? I tried a few numerical values, this integral should converge... right?

Hello, I have a problem with a system of ODEs. The three differential equations are as follows: diff(c(t),t) = 2*(c(t))^2 + 21/50*c(t) - 1/100*(h(t))^2 - 1/5*c(t)*h(t) - (9/2000)*h(t) + 49/4000; diff(h(t),t) = h(t)*(c(t) - 1/5*(h(t)-1)); diff(k(t),t) = 8/100*k(t) - h(t) - 1/5*k(t)*h(t); diff(c(t),t) = 2*(c(t))^2 + 21/50*c(t) - 1/100*(h(t))^2 - 1/5*c(t)*h(t) - (9/2000)*h(t) + 49/4000; diff(h(t),t) = h(t)*(c(t) - 1/5*(h(t)-1)); diff(k(t),t) = 8/100*k(t) - h(t) - 1/5*k(t)*h(t); As t goes to infinity the three variables c(t), h(t), k(t), respectively, approach certain values -in this setting 1/50, 11/10, 55/3, respectively- with the values of the derivatives converging to 0. (The point is saddle path-stable.)

Hi all, I am just curious about this problem, which has been in my mind for long time. I have seen some complex-valued functions, which are not in closed-form. For example, the complex-valued functions are defined by ODE: y'(t)=a+b*y(t)+c*(y(t))^2 + ... where the numbers in above ODE are complex-valued and the complex-valued functions are defined by functions of y(t), such as exp(y(t)), etc. Such ODEs can only be solved numerically. Sometimes even a closed-form solution is available, we would rather choose to solve it numerically because the closed-form solution often involves hyper functions and super complicated expressions.

I have the following:

>                 /             /         2          \\    
>              1  | 2    2      |/ 2    2\       2  2||    
>       eqn := - +\b  + a , sqrt\\b  + a /  - 4 a  c // - c
>              2                                           
                                                     (1/2)    
        1  2   1  2   1 / 4      2  2    4      2  2\         
 eqn := - b  + - a  + - \b  + 2 b  a  + a  - 4 a  c /      - c
        2      2      2                                       
>                          solve(eqn, c)
                               2    2

Here are some possible bugs or limitations that I have come across while working with Tensors in the new physics package. I have done best of my efforts looking into the documentation, but it is still possible that the bugs I am listing are not bugs at all but outcome of lack of my knowledge in using Maple. My intention of creating this blog is to not to criticize but to help the Physics package development team in making updates. I appreciate their efforts for developing a much needed package for areas like fluid mechanics, continuum mechanics, theory relativity etc. Platform I am using: Maple Ver 11.01 on Mac OS X 10.4.10