Why does collect only work sometimes?

I will show with a simple example.  I can do this

a := 5*x^2-4*x+3;
       
                             a := 5 x²  - 4 x + 3
h := exp(x)*a+exp(x);
            ...

How to get the polynomial successfully why return error expect a series valuation 1, what do it mean?

l := [12,14,27,35,46,49];
sl := listtoseries(l,x,revogf);
convert(sl,ratpoly);

with(gfun):
gfun['maxdegcoeff'] := 50:
gfun['maxdegeqn'] := 2:

i use number of balls in each basket to get a list, but all functions return fail? where is wrong? and how to use correctly?
l := [0,0,0,2,0,0,0,0,1,1,0,1,0,1,1,0,0,0,0,0,0,1,0,0,1,0,1,1,0,1,1,0,1,0,2,0,0,0,1,0,0,0,0,0,1,1,0,1,1]:
listtoratpoly([1,1,2,3,5,8,13],z);
listtoalgeq(l,y(x));

l := [12,14,27,35,46,49,31];
listtohypergeom(l,z);
guessgf(l,z);

Hi, 
I'm modeling a magnetic field and I don't know how to plot the corresponding vector field:

For each point  M I have the vector B(M) as a list.
Could you explain me how to transform it as a "real vector" first and how to plot these vectors then??

Thanks in advance! 

Hello!

I've got a question about model integration process.

I've tried to solve quite complex mechanical model and this messages have appeared.

Computing initial conditions...
Iterate re-initialization...
done.
Simulating...
CreateDataRecord: using dsolve method=rosenbrock_dae
Generating configuration 1
Integrating configuration...
Re-initializing after event at t=4.94271387307997e-009...

How could we get module which contain this export, for example

I have

m1 := module export a; end module;

 temp := m:-a;

evalb(temp = a);
 # false
evalb(temp = m:-a);
 # true 

 but how could I get back the module like this

temp2 := getModule(temp); 

temp2;

 # m

evalb(temp2 = m) ;

# true 

Hi,

I'm trying to model a magnetic field with maple.

In order to do that, I compute a (huge) sum and integrals of real and posive numbers.

The problem is that for some points, when I compute the norm of this field I get an imaginary number with a very small imaginary part (egs -2, 27293.1844462+1.42305652280*10^(-84)*I ).

How can I get rid of it?

thx in advance 

Can anyone explain this?

> A := Matrix(7, 7, {(1, 1) = 0, (1, 2) = 0, (1, 3) = 0, (1, 4) = 0, (1, 5) = 0, (1, 6) = 0, (1, 7) = 0, (2, 1) = 0, (2, 2) = 0, (2, 3) = 0, (2, 4) = 0, (2, 5) = 0, (2, 6) = 0, (2, 7) = 0, (3, 1) = 0, (3, 2) = 0, (3, 3) = 0, (3, 4) = 0, (3, 5) = 0, (3, 6) = 0, (3, 7) = 0, (4, 1) = 0, (4, 2) = 0, (4, 3) = 0, (4, 4) = 0, (4, 5) = 0, (4, 6) = 0, (4, 7) = 0, (5, 1) = 0, (5, 2) = 0, (5, 3) = 0, (5, 4) = 0, (5, 5) = 0, (5, 6...

Mapleprimes has really painfully slowed down in the last day.  What's happened?

After I post this message mapleprimes will refresh and refresh a few times (not that it hasn't done that before) but now that it's slower again, it's quite frustrating, I can't post even check primes for at least 15 minutes after a post.  Back to the old days of primes 2 I guess.  I can't tell if mapleprimes making progress but it seems like were going backwards just as much as we go forwards.

Good afternoon.

I have a problem.

i want ot add the procedure friccion(x1q1(t), x2q1(t), 1) into the dynamic system equation, because the fricction change with the velocity.

I don´t know how can solve that

Please help me o give some ideas.

thank you

30-03-2011-robot-man.mw

My question is very easy I have  and I want   how could I ask this to maple?

In particular my expression is 

Hello.

I can't find a very "basic" tutorial about data file plotting and I have very simple questions.

Assume that we have a file that contains :

0.5 0.2

0.3 0.9

0.4 0.1

0.7 0.6

The first thing to do is to read data. I have no problems for that :

mydata:=readdata("test.txt",2)

Then

mydata=[[0.5,0.2],[0.3,0.9],[0.4,0.1],[0.7,0.6]]

Question n°1

I draw tiles, i want to utilise un plot of an array 2 dimension. But i have had a good solution ?

I input data by hand :

> with(plottools);
> with(plots);

 > a := proc (i, j) options operator, arrow; polygon([[i, j], [i, j+1], [i+1, j+1], [i+1, j]], color = red) end proc; b := proc (i, j) options operator, arrow; polygon([[i, j], [i, j+1], [i+1, j+1], [i+1, j]], color = green) end proc;

Hi everybody,
i'm an italian student, i'd like to create a Maple Library Archive for Maple 11 (a .mla file) with the procedures i want but i don't know how to. Can anyone explain me?

(I want to create a .mla file with some procedures and then recall the library at the initialization of a new worksheet, so that i can use the procedures i defined)

For example, i would like to create a .mla archive with the 2 following procedures:

I'm trying to plot phase analysis for the Friedmann's equation, however when running the protocol and trying to plot these phase analysis, it comes up with error that rho wasn't allowed in the set of options!

Here's the code i'm having difficulty with!?!

> SFsys := proc (lambda, W, ics, T, v, u) local sys, flatF, rho0line, plot0, plotDSp, plotDSm, plotE, flatF_Plot, IC, df1, df2; 

sys := eval(DSys, {Lambda = lambda, gamma = W});