AOA... I want to solve the following system in maple pl help

sys_ode := diff(y(eta), eta, eta, eta)+3*y(eta)*(diff(y(eta), eta, eta))-2*(diff(y(eta), eta))^2+x(eta) = 0, diff(x(eta), eta, eta)+3*Pr*y(eta)*(diff(x(eta), eta)) = 0

ics := y(0) = 0, (D(y))(0) = 0, (D(y))(infinity) = 0, x(0) = 1, x(infinity) = 0

Help.mw

Hello,

As a means of encoding information, I'm working with nested array objects (I had originally used lists, but they became too large and Maple suggested that I use arrays). The nesting should be at most four deep, but the nested arrays can have varying lengths. In order to work with the arrays, I have a series of procedures that manipulate a given array and update the existing array object to contain the result. The issue that I have is that one of my procedures needs to simultaneously use both the original array and a modified version of the array, but once the modification is performed, the original version no longer exists.

Ultimately, my issue boils down to this: is there a clean (or messy, I'm not picky) way to duplicate an array so that there are two copies of the array in memory? Just writting Array2 := Array1 just creates another pointer to the same array in memory from what I can tell, so that doesn't work. There is a function copy, but it doesn't seem to work on nested arrays. 

For example, running the following does not modify Array2.

Array1 := Array([Array([1, 2]), Array([3, 4])]);
Array2 := Array([Array([1, 2]), Array([5, 6])]);
copy(Array1, Array2);

Indeed, neither does

Array1 := Array([Array([1, 2]), Array([3, 4])]);
Array2 := Array([Array([1, 2]), Array([5, 6])]);
copy(Array1(2), Array2(2));

Unfortunately, the latter case would seem to mean that I can't just write a procedure to recurse through my layers of arrays and copy piecewise either.

Thanks in advance for any help.

Can anybody tell me what I'm doing wrong?
Or does anybody have some tips for things like this? (Things like this occur often)

Stephan

Hello,

Anyone can help me with the problem ?

I want to solve b1..b50

> restart; with(plots); with(LinearAlgebra); with(Statistics);
> m0 := proc (t) options operator, arrow; 1-exp((-1)*t*.5) end proc;
t -> 1 - exp((-1) t 0.5)
> m := proc (t) options operator, arrow; (1/(1+exp(-t+5))-0.67e-2)*1.0067 end proc;
/ 1 \
t -> |--------------- - 0.0067| 1.0067
\1 + exp(-t + 5) /
> n[max] := 10; delt := .2; n := n[max]/delt;
10
0.2
50.00000000
> T := Vector(50);
> b := vector(50); evalm(b);

> for i from 2 to n do T[i] := T[i-1]+delt end do;
> fun := proc (t) options operator, arrow; add(b[i]*m0(t-T[i]), i = 1 .. n) end proc;
> fun(t);
> fu := vector(50);

> for x to 49 do fu[x] := fun(x*delt) = m(x*delt) end do;
> s := solve({fu[1 .. 50]}, {b[1 .. 50]});

Thanks,

gerst

Hello,

sometimes I observe extreme delays when simply entering a variable name like fooBar; right after starting a Maple session. This happens when the current directory contains a file with that name, because Maple automatically loads this file.

For example, if I create an empty file fooBar.m and start a Maple session,

> fooBar;
Error, `./fooBar.m` is an incorrect or outdated .m file

raises an error. More often however, I have some huge Maple files in the working directory and whenever I use (by chance) a variable name in the Maple session that matches a filename, Maple tries to load the corresponding file.

Is there a documentation of this behaviour and a possibility to stop this automatic loading of files?

Thanks,

Erik

When trying to solve a set of partial differential equations, I always get the following error. I don't know what it means. Can somebody help me?

I've got a very complicated integral, generated by Maple (15), of the form:

Z:=a*Int(f(x),x=0..1);

I need to do some manipulations on the integrand.  So, I perform the following:

f(x)=GetIntegrand(Z);

f1:=perform operations on f(x)...etc

Z1:=a*Int(f1,x=0..1);

The trouble arises because sometimes Maple writes Z as shown above, and sometimes it writes it as:

Z:=-a*Int(-f(x),x=0..1);

and you can run the program twice in a row and you will get either form, randomly. So, sometimes Z1 will be wrong by a minus sign because you can't predict whether the minus sign is going to be embedded or not.

I've been complaining about this Maple property for years, to deaf ears within MapleSoft who insist it is not an issue, and it has been the subject of long discussions on this site that go nowhere.

So, the question becomes - how do I reliably extract the expression "a" from the expression for "Z" and how do I test whether it has a minus sign embedded within it, or explicitly showing.

This can drive you crazy if you are trying to do a calculation or write a program that always works.

write down the mapple procedure that finds the shape operator plus
gauss and primative curvatores and determines the surface characteristic
of a parametically given surface

best regards, ty

I just wanted to remind everyone that this quarter's Möbius App Challenge closes on March 31st.  The next prize to be awarded is an Xbox One Prize Pack.  Video games are supposed to be good for the brain, after all, so really, you owe it to yourself to enter.

To enter the contest, all you need to do is:

1) Create an interactive App in Maple

2) While in Maple, log-in to the MapleCloud through the MapleCloud palette.

3) Click on the Send Document to the Cloud button

4) Set the group to "Mobius@admin", then hit send.

The group is moderated, so it won't appear instantly, but once approved it will appear on the Möbius Project server, where people can interact with it through a web browser, in Maple, or download it for use with the free Maple Player.

Here are the full contest details and more information on creating and submitting Apps.

Good luck!

Kim

Say I have a 3x3 matrix with real entries (like 3.4) and want to compute, say, A^(11). How can I do it and only have 5 digits in the output? I set Digits:=5; and used MatrixPower -- but got 10 digits, which is way too many for the classroom presentation.

Please see the attached worksheet for the error at the end, any idea what happens?

Besides, anyone know how to make plot array with each element has a plot and scatterplot in it?  I made my plot by making table first and then type the cmd individually.

Fitting_worksheet.mw

I also used a lot for for loop in this worksheet, can anyone suggest another way of doing it? And I think I initiated many Array(1..3) that is of no use.  But if I do not initiate and do the following

A[1]:=a : 

A[2]:=b:

A[3]:=c:

A;

output: A

Only if I initiate A:=Array(1..3) and then define the element I can see the complete A array at the end.

Is it possible to set maple to fill in a header or footer for every new document I make?

Now i have to do it fot each new file by hand: 

View => Header footer ..=> 

 - select custom  - goto tab cusom headers put in the left textfield "&[File] pag. &[Page]/&[Pages]"

Hi,

I want to calculate a range.

eg. j=1...n-1 will use this equation

P(j,n):={((m/(2-1))(m/(2))^(j-1))/(2(m/(2))^(n)-1))} 

j=n will use other equation.

How to create the command? I keep receive errors.

Thank you.

Lina

Dear All,

I would like perform a symbolic integration to the following integrand with Heaviside function:

The integral I defined is as follows:

The output I got is

Could any one explain me how to avoid the undefined in the output. I tried to define the assumtions to constrain the solution. However, I failed to supress the undefined.

I expect a result of the integration should also be piecewise function.

Appreciate you constructive inputs.

Thanks!

restart:with(plots):

TSol:= f(x,y,Q); # The actual funtion is in the attached maple sheet because of its size.

animate( plot3d, [TSol,y=-1..1,x=0..1], Q=0..2,contours=65,style=patchnogrid, grid=[80,80], orientation=[-360,-180], lightmodel=light4, shading=zhue, transparency=0.3,style=contour);

plot3d(subs(Q=2,TSol),y=-1..1,x=0..1,contours=65,style=patchnogrid, grid=[80,80], orientation=[-360,-180], lightmodel=light4, shading=zhue, transparency=0.3,style=contour);

For Q = 2, why there is a big difference between these two ouputs?

 3d_anim_try.mw (If the maple sheet is not accessible then let me know, I will copy past the function (f(x,y,Q))?)