Ok so i have a matrix M filled with complex roots of unity. I want to execute the following code but it seems to be failing to do so correctly

t:=exp(2 Pi I/11);

m := (i, j) -> M[(i mod 11)+1, (j mod 11)+1] ;  

mu :=(i,j)->(add(add(add(a[k]*a[m]*a[n]*t^(m)*m((i+k-m),(j+n-m))),n=0..10),m=0..10),k=0..10));

Something is wrong with my indexing of the matrix . or when the mod procs.

restart:with(plots):with(PDEtools):

 pde:=1/r*diff(r*diff(U(r,z),r),r)+1/b^2*diff(U(r,z),z,z)=0;

ans := pdsolve(pde);

ics:=(D[1](U))(0, z) = 0,(D[2](U))(r, 0)-B*U(r,0) = 0;

bcs:=(D[2](U))(r, 1)+B*U(r,1) = B,(D[1](U))(1, z)+B*U(1,z) = 0;

B:=1:b:=1:

S:= pdsolve(pde, {bcs, ics}, numeric);

Error, (in pdsolve/numeric) unable to handle elliptic PDEs

anyway around this?

RIZPDE.mw

I have a matrix with repeated columns

with(LinearAlgebra):

Q := Matrix([1,1,1,0,0,0,-2,-1],[0,0,0,1,1,1,0,-3]);

I'd like to write a loop that defines u[1],...,u[n] to be the unique columns of Q. Is there a way to do this?

I'm writing some code that computes a positive integer N and I'd like Maple to define a function of N variables. I've tried writing 

f := (seq(t[i],i=1..N))-> MY EXPRESSION;

but I receive the error

Error, invalid parameter; functional operators require their parameters to be of type symbol or (symbol::type)

Is there anything I can do here?

123.mw

i make two component that the left named MathContainer0 and right named MathContainer1

which can enter any numers on it

and i want to solve the eqution such as  

x*%MathContainer0+y*%MathContainer1=0 ,and y*%MathContainer0+x*%MathContainer1=0

but it still not shows the answers i want

anyone can help thx

Hello everyone!

I'm working with Maple for 8 years and this is the first time I encounter such a problem:

I solve a linear ODE system for my quantum Mechanics research and i want to calculate a quantity formed by the solutions of the system. Everything is going fine with laplace transformation and the symbolic answer is very fast although extremely big (it uses RootOf simplification)

When i use evalf to take numerical approximations of the quantity, the answer is very fast. OK

When i leave unspecified two parameters in order to get a 3d plot the answer takes about 40mins to appear. I think it is too slow but anyway, i can live with it. OK

I want this 3d plot for different parameters of the ODE so i have to do the above process many times. But for some parameter values of the ODE, i get a 3dplot for which:

1) The display of numpoints (surface and line) is incorrect.

2) Plot gets deformed as long as i rotate it!!! The orientation angle changes the appearance of the plot, something obviously unacceptable. I have access to maple 17, 15, 14, and 12. Maple 17 and 15 exhibit this behavior (64 bit Maple editions). But when i tried with Maple 12-standard interface(64 bit) and Maple 14 -Classical interface (32bit) everything went fine, but at the cost of  300 extra secs. I got a solid 3d-plot that is invariant under rotations.

My video card is Ati radeon 6800 HD and i installed the latest drivers. I don't know why is this happening. I thought of putting the blame on me, but in maple 12 and maple 14 everything is fine. It is a pity, because Maple 17 gives very nice and smooth 3d plots.

The first plot is the correct one with maple 12. The second is produced with maple 14. All good.

The third and the second are produced with different orientations of the same plot (Maple 17). Wrong display of data and change of image after rotation. The final one is again from Maple 17 but with style=points. It is in is in full agreement with the first two plots. 

Conclusion: Style=surface and line doesnt produce the correct plot, while style=point does. As for hardware acceleration, i unticked it with no results.

Extra information: When i try to open the maple 12 worksheet which is correct, with Maple 17, again i take the wrong displayed and unstable picture. Moreover only maple 14 classical edition works well. Maple 14 standard interface is also pathological.

Heeeeelp guys!!!

hi 

what is problem ?

Download u(x_y).mw

i want to define a loop for like this : 

for i from 0 to 100 by 0.2 do; ... ; od ;

i want when this loop finishes,the the loop turns to exactly vice versa respect,and continue , i mean it continue like this :
for i from 100 to 0 by -0.2 ...  , 

can anybody help me to find an algorithm for this ? tnx in advance

I am trying to color a sphere according to the following function and I am having some difficulties. Suggestions are appreciated.

((5x^2y^2)-6x^4)\((1-y^2)(x^2+y^2)-(y^2(1-x^2-y^2)).

Thank you

Dear people in Maple Primes,

I have a question about how to solve a system of equations.

In the following equation, I want to eliminate D(a).

x := D(a*b*c = 3*d); 
y := D(a^2*b^3*c = 3*a);

For this purpose,

a code of 

d_a := isolate(x, D(a));

eval(y, d_a);

works well. But, for me, this code is a little laborious.

Is there any better way than the above way?

Thanks in advance.

taro yamada

How to create a long progression in maple (up to 100 000 000 000), where a member is a previous one plus a certain number. For example: 25, 50, 75, 100... and then divide the whole series (all the members) by a number. What command should one use?

Hi all,

I try  to plot phase portrait the below DAEs, 

diff(S(t), t)=-β*(1+δ*sin2Πt)*S(t)*I(t)-μ*S(t)+μ,

diff(I(t), t)=β*(1+δ*sin2Πt)*S(t)*I(t)-γ*I(t)-μ*I(t),

0=S(t)+I(t)+R(t)-1.

where

μ=0.01,

β=1510,

δ=0.02,

γ=50,

I really appreciate your help.

a:=rand(0..8):
b:=rand(0..8):
c:=rand(0..8):
d:=rand(0..8):
e:=rand(0..8):
f:=rand(0..8):
a()+b()+c()+d()+e()+f()=8;

This is my  programming code.

I want ot set six random summation is  8. 

But the random summation can't reach 8.

Hi, 

  I would like to a string of characters to a file. For example,

***

str:="hello world";
WriteFile[APPEND]("D:\\output3.txt", str);

***

  It doesn't work. I did not get output3.txt :(  How should I do, to write a string of characters, such as "hello world" to a file?

Thank you

hi

please help me :

BC1 = diff(T(x, 0), y)=1000

BC2 = diff(T(x, 0.000025), y)=2000

IC = T(0,y)=0

where :

u(y)=-1.218493440*10^11*y^2+4.244913600*10^6*y+0.033

Download PDE_Sol.mw