## Maple 16 Questions and Posts

##### These are Posts and Questions associated with the product, Maple 16

Hello every one,

I am using similarity transformation to transform a PDE into an ODE.

I got the ode but its in a very ambiguous (unclear) form.

I need help to have the ode in a more friendly reading format.

Thanks

pdetoodest.mw

## empty implicitplot...

Hello,

I am trying to analyse a nonlinear ode. To see the behaviour,

I am using implicit plot (suggested by @Preben Alsholm).

The problem is that every time I need to search for the value of N

(=infinity) to have some sort of graph (needed for analysis).

The other thing is, if we have an output of the implicitplot, How we can be sure

that it is the correct one?

## What is this procedure trying to accomplish?...

> G := proc (N)

local s, n;

s := 0.;

n := 0;

while n < N do

n := n+1;

s := s+1/n

end do;

[s, n] end proc;

Comput  G(1.0),G(2.0), .....G(7.0)   try to figure out what
the procdure G is doing

## Warning, premature end of input...

`restart:with(plots):with(plottools):with(stats):unprotect(D):a[1]:=0:a[2]:=0.2:a[3]:=-0.15:a[4]:=0.85:b[1]:=0:b[2]:=-0.26:b[3]:=0.28:b[4]:=0.04:c[1]:=0:c[2]:=0.23:c[3]:=0.26:c[4]:=-0.04:d[1]:=0.16:d[2]:=0.22:d[3]:=0.24:d[4]:=0.85:e[1]:=0:e[2]:=0:e[3]:=0:e[4]:=0:f[1]:=0:f[2]:=0.2:f[3]:=0.2:f[4]:=0.2:p[1]:=0.01:p[2]:=0.08:p[3]:=0.15:N:=10000:x[0]:=0:y[0]:=0:randomize():for n from 0 to N dor[n]:=rand()/(10)^(12);if r[n]then i:=2 elif r[n...`

## Ndynamics package...

Does any one has any idea about "Ndynamics" package?

Whenever, I try to call it, maple gives this error

restart:

with(Ndynamics);

"Error, invalid input: with expects its 1st argument, pname, to be of type {`module`, package},

Is this an old package and replaced by a new one?

Thanks

## Strange Errors?...

I find I have a number of strange and unrelated errors.  I am new to Maple, but have been using Mathcad so am somewhat familiar with these systems.

One of the problems I have has to do with confusion between literal and standard subscripts.  I find it difficult to get Maple to recognize literal subscripts using any of the recommended methods.  When I do get it to work, and I'm not sure what I'm doing wrong, when I paste pieces of...

## using DEplots........

`Consider the differential equation                    d                                            --- y(x) = 2 y(x) (y(x) - 4)                   dx                          on the rectangle  -1 < x < 1, -2 < y < 7.40 in the xy-plane. (a)  Use DEplot to plot the direction field for the differential equation on the given domain.  Assign your answer to my_plot_1.`

## writing a function using procedures...

`Write a function to compute the n-th partial sum of the alternating series            1-1/(4)+1/(9)-1/(16)+...+(-1)^(n-1)*1/(n^(2))`
`Specifically, the procedure takes n as input, and returns the sum of the first n terms. `
`Can someone help me with this? I'm not very good at using procedures.`

## Sort Eigenvalues and Eigenvectors...

Heey

I have a problem when I call the Eigenvectors i get:

>Eigenvectors(Transpose(K).K);

i get the answer i want but every time i execute the worksheet my eigenvalues swich places aswell as the eigenvector.

Someone that can help me how i can sort or something like that to freeze the eigenvector output? so i can use some of the output to caluculate furhtere on and when i execute the worksheet i know that me eigenvectors and eigenvalues...

## write proc for alternating series and return nth p...

` Write a function to compute the n-th partial sum of the alternating series                    "1-1/(4)+1/(9)-1/(16)+...+(-1)^(n-1) * 1/(n^(2))"         Specifically, the procedure takes n as input, and returns the sum of the first n terms. `
` `
`So I am kind of lost- I've tried 5 different procs but keep getting more confused. Here is current one:`
` `
` `
`prob := proc (N) `
`local a, u, n, q; `

## Need help trying to figure out what the procedure ...

` G := proc (N)`
` local s, n;`
` s := 0.;`
` n := 0;`
` while n < N do `
`n := n+1;`
` s := s+1/n`
` end do;`
` [s, n] `
`end proc;`
`             G := proc (N) local s, n; s := 0.; n := 0; while n < N do n := n+1; s := s+1/n end do; [s, n] end procCompute  G(1.0),G(2.0), .....G(7.0)   try to figure out what the procedure G is doing`
`> G(1.0);`

## Simulation of Brusselator with diffusion...

Hi, there, maple built-in help just has an example of Brusselator model in 1D case. But how can I intepreter the diffusion terms that Brusselator has in 2D case? Could you please give me an example of the code to run Brusselator simulation in 2D case?

Brusselator model:

http://hopf.chem.brandeis.edu/yanglingfa/pattern/bruss/index.html

Thank you

Kyle

## got an error, while running the code...

i got error while running the code.

restart; de := diff(f(y), y, y, y, y)+2*W*(diff(f(y), y, y, y))^2+3*(diff(f(y), y, y, y, y))*(diff(f(y), y, y))-(M*M)*(diff(f(y), y, y))+G*(diff(theta(y), y, y))+B*(diff(phi(y), y, y)) = 0, diff(theta(y), y, y)+Nb*(diff(theta(y), y))*(diff(phi(y), y))+Nt*(diff(theta(y), y))^2 = 0, diff(phi(y), y, y)+Nb*(diff(theta(y), y, y))/Nt = 0, f(h1) = (1/2)*F, f(h2) = -(1/2)*F, (D(f))(h1) = -1, theta(h2) = 1, phi(h2) = 1, (D(f)...

## Solving equation system...

Hello,

I'm really new in Maple so the problem I have may look somewhat trivial. I have to solve a system of equations for two variables (V and alpha). All the expressions shall be reduced at the end in three (Assuming that 2 of them will be dependent). The code I've written is:

`> Vax := proc (V, alpha) options operator, arrow; V*cos*alpha-w*cos*(phiW-phi) end proc;> Vay := proc (V, alpha) options operator, arrow; V*sin*alpha-w*sin*(phiW-phi) end proc;`