I have a system of equations where unkowns are functions of variables
` > eqns:= {a(s,y,z,t)+2*b(s,y,z,t)=0,3*a(s,y,z,t)-5*b(s,y,z,t)=0}; `

I would like to get the matrix associated to the system.
I tested genmatrix but maple returns `equations are not linear `
Anyone have an idea of how to do this?

I have a large set and I would like to do the following efficiently:
1) use selectremove to split off a part of the set, based on a function f
2) map a function g onto the selected set
3) (optional) map a function h onto the removed set
I don't actually need 3) however I think it would be useful.
My problem is that the function g is easily computed while computing f, so something like the following is 2x too slow:

S, R := selectremove(f, big_set);
S := map(g, S);

On the other hand, g outputs a result of a different type, so I can code g to return the identity unless the condition in f is satisfied:

I get RootOf(_Z^2-3, label = _L2) in an answer. My understanding is that RootOf _Z^2-3 would be a root of Z^2-3=0 or plus or minus the square root of 3, but after reading the RootOf help sheet I still cannot figure out what label = _L2 means. My gut feeling is that it means one of the two roots, either -sqrt(3) or +sqrt(3) but that bothers me because I think that both are ligitimate solutions to the problem. Could someone please explain what label = _L2 means? The help sheet says something about label=e where e can be anything which wasn't at all helpful. Thanks. P.S. The problem that provided this issue is solve({x^2-y^2=y,2*x*y=x}) and in the second equation the x on each side should not be cancelled because x=0 is one solution.

I would to get some ideas on how to write a maplet code that will animate step by step how to draw a rectangle ABCD:
Draw side AB, and after this is done without removing side AB, draw side BC, and after this done without removing sides AB and BC, draw CD, and after this done without removing AB, BC and CD, draw DA.
Although this is not really my problem, it is similar to the animation I am trying to create. Rectangle ABCD is constructed without user intervention.
Thank you for any assistance you may come up with.

Using _EnvAllSolutions:=true; with solve(sin(x)=1,x)the answer returned is 1/2Pi+2Pi_Z1~. The Maple User Manual on page 82 says that Maple uses variables of the form _ZN~ to represent arbitrary integers thus my understanding is that the answer returned can be interpreted as 1/2Pi+2nPi where n is any integer. Correct?
Now for the more difficult situation where I an not sure my understanding is correct. Using _EnvAllSolutions:=true; with solve(sin^2(x)/x,x)the answer returned is Pi(2_Z1~+_B1~). In this case, the -Z1~ is again any arbitrary integer but _B1~ is quite different. Using about(_B1~) the return tells me that _B1~ is assumed to be : OrProp(0,1).

I am having this common problem when solving trig equations. I read "?solve" but missed something somewhere because I still don't know how to solve this problem. Taking a simple example of solve(sin(x)=1,x) the answer returned is Pi/2 and while Pi/2 is a correct answer, because of the periodic nature of the sin function there are others. So maple for some reason (which doesn't make sense to me at all)is limiting the range/domain and therefore not providing the complete answer which is Pi/2 +2nPi where n is any integer. I tried to force Maple to consider a larger range by using assume(0<>

I installed Maple 11 into my Ubuntu 7.04 machine, and I'm having a problem to make the arrow keys work when I running maple classic worksheet. All the other keys on my keyboard works fine, but Maple won't response when I hit the arrow keys(up, down, left, right). It's a problem that only shows up in "Maple classic" (xmaple -classic).
Any suggestions?

When I enter solve((sin(x))^2/x=0,x) in Maple 11, nothing is returned. When I enter the same thing in my voyage200 calculator, the correct answer of x=@n1*Pi where @n1 is any integer constant is returned. Why can't I get maple to produce the correct answer? Is this a bug?

What does the term Tool Box mean as used with Maple?

Hi!
I have an external library with this function:
```
double test(double x)
{
return sin(x);
}
```

In Maple I am doing this:
**test := define_external('test', x::(float[8]), RETURN::(float[8]), LIB = "Test.dylib");
f := x->test(x);
**
Now when I call f(2) for example, I get 0.909297426825681710 back.
But if I try this:
**plot(f(y), y = 0 .. 2);**
I get this error message:
`Error, (in f) invalid input: test expects its 1st argument, x, to be of type numeric, but received y`

I think I need to somehow convert the (possible) symbolic input of f into a float[8] before it is passed to the procedure test, but I can't figure it out.

Dear All,
Does anybody know how to plot a surface in 3d with only those points which satisfy a constraint?
In particular I'm plotting the surface defined by the equation F(beta,Omega,delta)=0 using implicitplot3d. Unfortunately, I want to command Maple to leave out any points which violate the inequality h(beta,Omega)>0.
Does anybody know how to do this?
cmichael

Dear Sir or Madam,
There is a maple code below for finding all paths between two given pair of vertices. Is there any maple code available for finding all minimal cut sets ( i.e., components whose failure will results in a network failure) between any given pair of vertices?
For example, a bridge network:
>with(networks):
>G:=graph({1,2,3,4},{{1,2},{1,3},{2,3},{2,4},{3,4}}):
Question:
Find all cuts between node 1 and node 4.
Doing it by hand, I got: [{1,2},{1,3}],[{2,4},{3,4}],[{1,2},{2,3},{3,4}],[{1,3},{3,2},{2,4}].
It is not easy to enumerate all cut sets by hand when the network is large. How do I code it in Maple??

Hello,
I have expressions of the form

`e[i,j,k]:= s*U(s)*a(s,y,z,t)+ s*(s+1)^2*b(s,y,z,t)+ ...`

where `e` is a symmetric array, i=1..4, j=1..4, k=1..4
and function a(s,y,z,t),b(s,y,z,t),c(s,y,z,t),f(y,z,t),g(s,y,z,t),... and their partial derivatives are appearing in these expressions
I exracted different coeff, named them,
and then I wanted to rewrite each e[i,j,k] while substituting coeffs with implicit function, so I've used `applyrule` in a procedure but not all coeffs are substituted.
Can anyone help please.
Here is my worksheet

View 4780_beny1.mw on MapleNet or

Download 4780_beny1.mwView file details
Hello!

I use Maple 9 for some weeks and it helps me a lot. In the last days I have 2 problems that I could not implement in Maple. I spent many hours reading manuals, tips etc. without finding an idea, so I decided to post here my questions:

I use dsolve (numeric) to solve a system of ODEs. I receive the solution "p" wich I can plot whithout problems.

Question 1

----------

After this, I define a new function "S" as:

S := t -> p(t)[2] + p(t)[3] + p(t)[4] + p(t)[5];

I tried to plot it with

e:=1.5;

interface(plotoutput="sum.ps");

plot(S, 1..e);

but I receive the message

I am trying to import data from Excel and re-create the scatterplot that is on the Excel spreadsheet. The first column contains the Y data. The second column contains the X data. I can import and browse the array of data but I cannot create a scatter plot of the data. I want to fit a function to the data and overlay this function on the graph to visually see how well the fit is.
Thanks.