Hi all

I have the following ordinary differential equation, where all the parameter used are constant ( A,B,C,D,E,F,G,H).

Is there any technique gives a solution
diff(y(x), x$2)+(A/x+B/x^2+C)*(diff(y(x), x))+D*(diff(y(x), x))^2/x+E*(diff(y(x), x))^3+F/x+G/x^2+H/x^3 = 0;

 thanks for your help

Dear all;

I hope an idea to solve the following problem.

P(n,t): probability at time t

Lambda and mu : two given parameters ( can be fixed ), and we assure mu greater then lambda

 t : time parameter ( we can say that 0<= t <=T , and T fixed ) 

 for n an integrer  greater then 1 we have the following equation

eq := diff(P(n, t), t) = -(lambda+mu)*P(n, t)+lambda*P(n-1, t)+mu*P(n+1, t);
 

for n=0, we have

ics := diff(P(0, t), t) = -lambda*P(0, t)+mu*P(1, t);

How can we compute P(n,t) ,

is there an exact solution or a numerical method to get the value of P(n,t)

Then we plot( P(n,t),t=0..100) ;

Many thinks

Can somebody please help me with this assignment?
Struggling a bit with the Euler-method from task d) and further.

Download luythua.mw

From the screenshot we see that Maple has correctly replaced a in the defintion of s. But it has not incorported v[B]. I was a SMath (free from internet) user and this was a simple operation.

Thanks for any advice.

SymbolicEval.mw

How do you can convert g into ?

Can you help me?

Hi

I am trying to evaluate a function that contains an infinite sum. I need to evaluate the integral to determine a CDF, and from that hopefully the inverse CDF in order to sample the corresponding PDF.

The sum comes from a 2F1 hypergeometric function, which I have written manually in the attached file.

Can anyone tell me if and how it is possible to evaluate this integral, with respect to x?

I have inserted an image below, but also the entire file :) Marginal2.mw

Thanks in advance.

Maple 2018 starts but block and hangs after the first imput.

Even after a clean install on a clean disk where there are no old files of maple.

My specs are: WIN10 pr 64/ I7 /16 GB/ SSD

Who has the same problem and a sollution?

Uxx + Uyy =0

      y is less than Pi,x is greater than 0

B.c are u(0,y)=0 , u(Pi,y)=sinh*Pi*cosy

              u(x,0)=sinx , u(x,Pi)=-sinhx

How can I compute MatrixInverse, MatrixMultiply and eigenvalues(eigenvectors) faster? are there any procedures or commands that can be used instead of those three command mentioned before to speed up calculations?

1.mw

In the above document, digits must be 30.

I want to know how to program a metric g_[ ]  so that entries are zero apart from the diagonal.
Basically I am using the physics package and can set it as arbitrary or can set it to be specific values but I just want arbitrary values across the diagonal. e.g
 

with(Physics);
Setup(mathematicalnotation = true);
                 [mathematicalnotation = true]

Setup(metric = arbitrary);
 [metric = {(1, 1) = _F1(X), (1, 2) = _F2(X), (1, 3) = _F3(X), (1, 4) = _F4(X), (2, 2) = _F5(X), (2, 3) = _F6(X),  (2, 4) = _F7(X),

(3, 3) = _F8(X), (3, 4) = _F9(X),  (4, 4) = _F10(X)}]

SO here I want to keep F1 F5 F8 and F10, thanks in advance!

THIS IS WHAT I TRIED:

 

with(Physics);
Setup(mathematicalnotation = true);
Setup(Coordinatesystem = (X = [x1, x2, x3, x4]), metric = f(dx1^2+dx2^2+dx3^2+dx4^2));
    * Partial match of  'Coordinatesystem' against keyword 

       'coordinatesystems'

  Default differentiation variables for d_, D_ and dAlembertian 

   are: (Xequals(x1,x2,x3,x4))
  Systems of spacetime Coordinates are: (Xequals(x1,x2,x3,x4))
Error, (in Physics:-Setup) expected definition of a metric as a tensorial algebraic expression with two free indices; received one with free indices {}

The attached worksheet shows how to evaluate and graphically analyze an autonomous first-order nonlinear recurrence with two dependent variables and multiple symbolic parameters. 

This worksheet shows how a small module that simply encapsulates the given information of a problem combined with some use statements can greatly facilitate the organization of one's work, can encapsulate the setting of parameter values, and can allow one to work with symbolic parameters.

Edit: In the first version of this Post, I forgot to include the qualifier "autonomous".  The system being autonomous substantially simplifies its treatment.
 

Download FoxesAndRabbits.mw

I have a solution to a linear ODE which is very long and complicated.  The solition clearly has some parts which are repeated and so it would would be easiest to express those repeated parts as something simpler.

For example, suppose I had

x = (-b + sqrt(b^2 - 4*a*c) ) /2*a

What is the command to take x and do someting like

Z = sqrt(b^2 - 4*a*c)

x = (-b + Z)/2*a

when plotting a polar function in terms of r and theta, is there a way to animate it?  

For instance I want to animate u(r,theta)=rcos(theta) for theta between 0 and 2Pi.

i have to list 
a := sort([.17, .23, .33, .39, .39, .40, .45, .52, .56, .59, .64, .66, .70, .76, .77, .78, .95, .97, 1.02, 1.12, 1.19, 1.24, 1.59, 1.74, 2.92])

b:=[5,seq(0,i=1..19)]:

i want to make aloop on a  by saying that for i=1 eliminate b[1] from a then sort the remining elements of a 

then for i=2 eliminate b[2] from a then sort the rest elimant of a and so on