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Dear Community,

I have a complicated function with two independent variables, namely QD( tD,  rD ). I would like to explore its behavior in a semilog plot in the range of tD = 1.0 .. 1000.0 with changing rDs, where I would like to change the values of rD with a slider of the Explore command. I've developed the attached code, yet it gives me an error message, "unexpected option... " Could you pls. have a look at it what do I do wrong?

Tx for the kind help in advance

best regards


Combining graphs...

September 22 2016 montse 5


Can anyone tell me how to combine several graphs into one? Fo instance I have one graph with x going from 0-1,another with x going from 1-20 and yet another with x going from 20-21. I can plot them individually but how do I put all three together?

I'm sorry I'm not doing a very good job explaining, but I hope it is understandable.





Thanks to the help of several list members I managed to translate and update some old procedures.  These procedures were part of a packcage and they all had help files.   Here is an example


# E. Mendes - 25/04/94

`FUNCTION: sampling - finds the discretized model`,
` `,
` sampling(f)`,
` sampling(f,k)`,
` sampling(f,k,vars)`,
` f - state space`,
` k - order of approximation`,
` vars - variables`,
`- sampling(f,k) returns a discrete approximation for a continuous`,
` system`,``,
` dx(t)/dt=f(x(t),u(t)) `,
`EXAMPLE: `,``,
`> with(linalg):`,
`> f:=vector([x2,x3,-x1+x2^2+2*x3]):`,
`> sampling(f,1)`,
` 2`,
` [- x1, x2 + x1 ]`,``,
`SEE ALSO: fixpoind, fixpoinc`):


I have browsed the help documentation but I must confess I don't feel comfortable to modify the help database.  Do I have to wrap all the functions up as a package and then write the help files?   I am lost here.  Any help will be most welcome.

Many thanks





I would like to silmplify a trigonometric equation with some squares. I'm sure this equation can be reduced but i didn't manage to simplify it with Maple.

Here is the equation (named condition in the maple file) that I would like to simplify:


May you help me to simplify this trigonometric equation?

I would like simplification if time the pattern cos()^2+sin()^2 appears.

Thanks a lot for your help

Pick any point P and let Q = (1, 1, 1). [Your choice for P can be anything other than the origin or

Find an equation for the line l1 that passes through P and the origin. Plot the line segment formed by P and the origin in Maple 

How would I plot this?

Please, I need assistance with this problem.

Here is the problem I am trying to solve:


myPDE1 := D11*diff(w(x,y), x$4) + 2*(D12+2*D66)*diff(w(x,y), y$4) + D22*diff(w(x,y), x$2, y$2) - G*diff(w(x,y), x,y)= 0;


pdsolve(myPDE1, build);

"Boundary conditions";
"(Note:the domain for the problem is a rectangle)";
bc1 := w(0,y) = 0; # @ x=0 edge;
bc2 := w(a,y) = 0;  # @ x=a edge;
bc3 := w(x,0) = 0; # @ y=0 edge;
bc4 := w(x,b) = 0; # @ y=b edge;
bcx1 := -D11*D[2](w)(0,y) - D12*D[2](w)(0,y) = 0; # @ x=0 edge;
bcx2 := -D11*D[2](w)(a,y) - D12*D[2](w)(a,y) = 0; # @ x=a edge;
bcy1 := -D12*D[2](w)(x,0) - D22*D[2](w)(x,0) = 0; # @ y=0 edge;
bcy2 := -D12*D[2](w)(x,b) - D22*D[2](w)(x,b) = 0; # @ y=b edge;

sol := [myPDE1, bc1, bc2, bc3, bc4, bcx1, bcx2, bcy1, bcy2];


and D11, D12, D22, D66 and G are constant.
The intention is to find the critical value for G"

I need help with how I can handle the boundary conditions for the problem. Thanks a million.


I want to join two animations, but displayed subsequently, not simultaniously, As far as I got, I have:

plot2 := plots[animate](plot, [tau[1], z = -(1/2)*J .. (1/2)*J, color = red, legend = shear*stress], h = 1 .. 1+1/sqrt(3));
plot3 := plots[animate](plot, [tau[2], z = -(1/2)*h .. (1/2)*h, color = red, legend = shear*stress], h = 0 .. 1);
display([plot2, plot3], insequence = true);

my functions are difined as

tau[1] := h-1+(4/3)*(1/sqrt(3)-h+1)*sqrt(3)*(sqrt(3)*((1/4)*J^2-z^2)/(J^2*b))
tau[2] := (4/3)*sqrt(3)*((1/4)*h^2-z^2)/(h^2*b)

Both plots work individually, however, they have successive ranges. I wondered if I could make 1 plot, with an if statement wether to plot tau[1] or tau[2] depending on where the animation is in the range h. Does anyone know about a solution?

I need  some examples s.t. the computation of their lexicographic Groebner basis is heavy?

Thank you so much.

Already searched and browsed multiple different threads and still cannot find a solution.

Apologizing the noob nature of this question.



In this code below, Why is the factor command not working?

f := a^2+x^2-2*ax;














Hello people in maple primes

I have a question, which is about the matrix shown in

Why can't C below be shown with beta?

A := Matrix(3, 3, [[-a, a, 0], [0, 0, -sqrt(l*b*c*(j+k))/(j+k)], [2*j*sqrt(l*b*c*(j+k))/((j+k)*l), 2*k*sqrt(l*b*c*(j+k))/((j+k)*l), -c]]);
C:=subs(j*alpha^(1/2) = beta,B);
e:=subs(alpha^(1/2) = gamma,B);

Best wishes.




From differential expression I am trying to extract coefficients corresponding to given indets, but the coeffs command is giving me error as "invalid argument to coeffs"

For example for worksheet titled "[852] Determining Equations using Prolongation" the error is showing for expression (9).

Whereas the same command in worksheet titled "[411] Determining Equations for Variable Coeff KdV(Reviewed)" is working okay and is giving desired result at (16).

I am running both worksheets in Maple 18.





Can anybody please tell, where I can find seminar/workshops on Maple training ?


Dear All,


I am a new Maple user and I am still unaware of a lots of fancy features of Maple. I have a problem of simultaneous fitting polynomials. I wish that I could have help from you. Say, we have two polynomials of two variables,



Note that a4 and a5 are shared by the two polynomials. I would like to fit the two polynomials against their respective data set. Is there anyway I can do it using Maple? Any of your help is highly appreciated!


Best regards,




HOW I convert root of in to another form


I'd like to find out what number Maple can still calculate the isprime for, and what number will make it go "No thanks, this is madness - ERROR".

I tried isprime (10100,000,000 + 2), and it can still calculate the result. No prime of course, that's the whole point of the +2.

I tried isprime(1010ˆ9 + 2) and it crashed.

But what is the tipping number?

I decided I should write a loop, and let maple write away the last number till it crashes. Is this possible? I think I'll need something like

> for n from 5 to ??? do isprime (10ˆn + 2) and ??? end do

This isn't suitable at all, but I cant figure out how to program "to error" or "write away this number"...


I hope the question is clear and look forward to ideas on how to make this work.


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