I need some help...i need a solver using the Runge-Kutta method adaptive size control, to solve a sytem of 5 diff eq's, all of them are interlinked...

And 

Say that dsolve numeric produces a results, called Solution, Now ex  solution(0)=1, and in general solution(t) can be evaluated, now, i want to use this, in E(t)=2*solution(t), in a plot, thus...

plot(E(t),t=0..100,....), but returns the error....

Ok, I am not a very experienced user, but I am mystified by this.  The essence of the problem is that when entering a range of values in an integration, I get a different answer if the range is given as 0..1 to if it is given as 0.0..1 or 0..1.0. Here is the program

### dgig
dgig := proc(psi, chi, lambda, t)
    (psi/chi)^(lambda/2)*t^(lambda - 1)*exp(-(psi*t+chi/t)/2)/\
    (2*BesselK(lambda,sqrt(chi*psi))):
end: ## End of dgig

Suppose I have a file of text that I would like to read into a Maple (16) worksheet as a string. (I have in mind encrypting the string using the RSA encryption scheme.)

If I paste the text directly into the worksheet and surround it by ",  I have no problem, but if I try to read, for example, a file some_text.txt using a command like

     read("C:\\Users\\MyName\\Desktop\\some_text.txt");

I've created a matrix in which each row has two values. I'm using Add(i,i=[matrixName][row element number])/2 to find the mean of each row, which I'd like to transfer to a corresponding element number in an array or a vector, but so far I can only get it to work on single rows or (if I use only Add(i,i=[matrixName]/2), understandably, the mean of the whole matrix. Is there a way to do it wholesale?

Hi! I need help with my project I dont know where to even start!

Question:

Consider a simple polymer , which consist of long chains of simple molecules attached to each other, e.g:

....-CH₂-CH₂-CH₂-...

If the interaction energy between consecutive sections ca be ignored or is low enough, the chain can be bend around at varios places to form varios configurations. One can start by  fixing the first section...

Hi everyone 

Is there a method in maple to plot a rectangular matrix.

Amr

See my code:

----------------

restart;

with(plots); with(PolynomialTools); with(LinearAlgebra);

f := (x, y) -> ((2*x^2+y^2*(x^2*(-2+sqrt(1/x^4+4/(x^2*y^2)+4/y^4+4))-1))/(4*x^2-2*y^2+4))^(1/2) ;

g := diff(f(x, y), x);

plot([g(.1, y), g(1, y), g(3, y)], t = 0 .. 10);

-----------------

Here is error message:

Warning, unable to evaluate the functions to numeric values in the region; see the plotting...

I did not come across with a sorting algorithm animation that allows me to enter my own data, so I decided to write one in Maple.

In this worksheet, you can create an animation on sorting the integers that you have entered. If you let the worksheet to generate the data for you, you can specify the sortedness of the data. This feature allows you to visualize how some algorithms perform better or worse on data of a certain characteristic: The time complexity may not be...

Hi.

I can explain my question on the simplified example:

sol1 := dsolve({diff(x(t), t) = x(t), x(0) = 0.0}, numeric); 

func := q -> op(2, op(2, sol1(q))); 

dsolve({diff(z(t), t) = func(t) * z(t), z(0) = 0.1});

But i take a throw. It is clear, because, I try to call op(2, sol1(t)). Which way I whould use to solve my problem?

Dear everyone,

  Hello,

  I have a stupid question. From

http://www.maplesoft.com/support/help/Maple/view.aspx?path=examples/string

  There are many examples about "" '' `` related to character string (let me call it in this way for a moment )

  Actually what is the precise difference between these symbols?

Thank you very much in advance

with best regards

Dear everyone,

  Excuse me, I made some editing work witn the result of maple in editplus, then copy the editplus result to maple. Then I received several ">"

E.g.

f1:=2;
f2:=3;

copy to editplus then copyback to maple, it becomes

>f1:=2;
>f2:=3;

I have to "shift+enter" in maple to create new lines without ">", then copy the content of one line with ">" to the new created line without ">".

Hi I have a problem with the resolution of an equation. When I tried to solve it it returns "solutions may have been lost"... Here is the problem:

restart:with(Statistics):
> x:=rand()/10^12;

                               197859430267
                          x := ------------
                               500000000000

> X:=RandomVariable(Gamma(2,4));

                               X := _R

> XL:=RandomVariable(ChiSquare(3));

I've the equation

(-x^2+eta^2+2*x*xi+2*x*eta-xi^2-2*xi*eta-2*x*y-2*y*eta+2*xi*y+y^2)*(-x^2-2*x*eta+eta^2+2*x*xi+2*xi*eta-xi^2+2*x*y-2*xi*y-2*y*eta+y^2)-(x-xi)^4+6*((x-xi)^2)(-y+eta)^2-(-y+eta)^4

The answer is 0

But I can't get the answer by simplify and expand

Then which .Thanks

We have the data
X := Vector([seq(.1*j, j = 0 .. 16), 1.65], datatype = float):
Y := Vector([2.61, 2.62, 2.62, 2.62, 2.63, 2.63, 2.74, 2.98, 3.66,
 5.04, 7.52, 10.74, 12.62, 10.17, 5, 2.64, 11.5, 35.4], datatype = float):
and the model function of x with 5 parameters
F := a*cosh(b*x^c*sin(d*x^e)):
How to fit F to the data  up to the sum of the squared residuals being about 0.001?
Is such good fit possible with Maple at all? It is interesting that Mathcad (not MATLAB...