Hello ,

2014_PDE_project.mw

I was using maple as a documentation software and was preparing some notes for my exam. 

The file now opens but most of the content is gone. Even the one which was properly saved.

I see Joe Riel 5676 has solved an earlier case like this. could somebody look at this and correct the file and upload it again please.

Hello: I'm looking over the Help section but I can not find a Maple package that has a command to compute the symmetric sum or the cyclic sum. I just started working with inequalities. Please could anyone recommend a package that allows me to compute expressions related to Muirhead's Inequality (see part 2 of  the answer:  http://math.stackexchange.com/questions/488967/majorization-muirhead)

I want to introduce a matrix of order M by M as for any m, M, pl help as show in file

Help.mw

Dear all;

Please I have maybe a simple question. I need to point these nodes in R^3 using Maple. Thanks for your help.

Tab := [[0, 0, 0], [1/5, 0, 0], [2/5, 0, 0], [0, 1/5, 0], [1/5, 1/5, 0], [2/5, 1/5, 0], [0, 2/5, 0], [1/5, 2/5, 0], [2/5, 2/5, 0], [0, 0, 1/5], [1/5, 0, 1/5], [2/5, 0, 1/5], [0, 1/5, 1/5], [1/5, 1/5, 1/5], [2/5, 1/5, 1/5], [0, 2/5, 1/5], [1/5, 2/5, 1/5], [2/5, 2/5, 1/5], [0, 0, 2/5], [1/5, 0, 2/5], [2/5, 0, 2/5], [0, 1/5, 2/5], [1/5, 1/5, 2/5], [2/5, 1/5, 2/5], [0, 2/5, 2/5], [1/5, 2/5, 2/5], [2/5, 2/5, 2/5]]

This table contains some point of R^3. How can I put these point.

Hi All,

I have a stupid question.

I wanted to distinguish the fuction of map and Map and tried some test.

Sometimes, the Map is identical to the map:

But sometimes not:

Maple Help seems not to explain the difference very clearly.

map_and_Map.mw

I'd appreciate any help on this topic. Thank a lot.

Dear all,

Please help in this question.

Using   I want to plot in R^3, the set of point u[i,j]^k . This point has as cordinate  (x[i],y[j],t[k]).

x := i -> (1/5)*i;  #  x[i] the x-coordinate
y := j -> (1/5)*j; # y[j] the y-coordinate
t := k -> (1/5)*k;  #  t[k] the t-coordinate

The name of point is u[i,j]^k

How can I  plot all the point.

 with(geom3d):

point(u[i,j]^k, x(i),y(j),t(k));

Thank you.

Hi all

Assume that we have the following colomn vector:

and we want to construct the following matrix:

How can we do this with maple????

Note that r is a variable and the dimension of matrix depend on r.

regards

Mahmood   Dadkhah

Ph.D Candidate

Applied Mathematics Department

Dear all;

I need a help in this question.

u(x,y,t) my solution of PDE. x,y space, and t=time.

In the case without t. .i.e. u(x,y). Here is a visualization of the lattice u(x_i,y_j). i=1..3, anf j=1..3.  Please try this example, it's working. 

my question, if i would like to add a third variable t, i.e.  and get u(x_i,y_j,t_k)  on each points. I would like to show the lattice in (x,y) plan for each t_k. I Think I will get many parallel lattice. 

Please can some one, modify this code to get the parallel lattice. Thanks.

with(LinearAlgebra):
with(plots):
with(PDEtools):
interface(rtablesize=20):

Here,

L := 'L':
N := 'N':
g := 'g':
Z := i -> -L+2*L/(N+1)*i;
x[0] = Z(0),x[N+1] = Z(N+1),y[0] = Z(0),y[N+1] = Z(N+1);

N := 4;
L := 1;
r := L/(N+1)/4;
ngon := (n,x,y,r,phi) -> [seq([x+r*cos(2*Pi*i/n+phi), y+r*sin(2*Pi*i/n+phi)], i = 1 .. n)]:
p[1] := display([seq(polygonplot(ngon(4,Z(0),Z(j),r,Pi/2),color=magenta),j=0..N+1),

seq(polygonplot(ngon(4,Z(N+1),Z(j),r,Pi/2),color=magenta),j=0..N+1),

seq(polygonplot(ngon(4,Z(i),Z(0),r,0),color=magenta),i=1..N),

seq(polygonplot(ngon(4,Z(i),Z(N+1),r,0),color=magenta),i=1..N),

seq(seq(polygonplot(ngon(20,Z(i),Z(j),r,0),color=white),i=1..N),j=1..N),

textplot([seq(seq([Z(i+0.1),Z(j),typeset(u[i,j])],i=0..N+1),j=0..N+1)],align={above,right})],view=[Z(-1)..Z(N+2),Z(-1)..Z(N+2)],tickmarks=[[seq(Z(i)=typeset(x[i]=evalf[2](Z(i))),i=0..N+1)],[seq(Z(i)=typeset(y[i]=evalf[2](Z(i))),i=0..N+1)]],

axes=boxed,scaling=constrained,labels=[``,``]):
p[1];

Hi All,

I used the command map to apply a procedure to elements of a array like this:

Why did I get the null array "[]"?

A vector was also used and got the similar result: 

I'd appreciate any help on this topic. Thank a lot.

i want to find initial condition for F(0),G(0), H(0) and thetap(0) which is are missing in this problem.. then i facing this error Error, (in dsolve/numeric/bvp) Newton iteration is not converging

Maple Worksheet - Error

Failed to load the worksheet /maplenet/convert/hydronew2.mw .

Download hydronew2.mw

Recently I started to learn to use maplesim. I wanted to set up a feedback system which is used to control the speed of DC motor. I don't know how to build it. Please give me some advice. I really appreciate your help.

Hi, with a list

l:=[1,1,1,2,3,3,4];

What's the best way to get the index(s) for the values equal to '1'?

Say for x=1, we want

[1,2,3]

for x=2, we want

[4]

ect.

I'm calculating the geodesics to a parametrized system in R³. When trying to solve the geodesic equations for a surface of revolution, I'm getting a strange error. The goal is to write the code for any parametrized surface, not just revolution (hence I didn't use the short cut for surfaces of revolution).

For the code, I find the first fundamental for, then the geodesics, then turn the christoffel symbols into a time-variant array. (Gamma for the position of (u,v) in the uv-plane, and C as the array so I can take derivatives with respect to time.)

The code for creating the Christoffel Symbols and the parametrization of the paraboloid:

restart; with(LinearAlgebra):
V := (u, v) -> <v*cos(u), v*sin(u), v^2+1>;

Christoff := proc (X)
local x1, x2, M, N, i, j, k, s, E, F, G, g, Q, Delta, Prelim, cyclicPrelim;
global Gamma, C; #GAMMA
x1 := (u, v) -> <diff(X[1], u), diff(X[2], u), diff(X[3], u)>;
x2 := (u, v)-> <(diff(X[1], v), diff(X[2], v), diff(X[3], v))>;
E :=  (u, v) -> DotProduct(x1(u, v), x1(u, v), conjugate = false);
F := (u, v) -> DotProduct(x1(u, v), x2(u, v), conjugate = false);
G := (u, v) -> DotProduct(x2(u, v), x2(u, v), conjugate = false);
simplify([E(u, v), F(u, v), G(u, v)]);
M := (u, v) -> <E(u, v), F(u, v); F(u, v), G(u, v)>;
simplify(M(u,v));
printlevel := 3;
Delta := simplify(Determinant(M(u, v)));
N := (1/Delta)*<G(u, v), -F(u, v); -F(u, v), E(u, v)>;
Q[1] := simplify(map(diff, M(u, v), u));
Q[2] := simplify(map(diff, M(u, v), v));
for i to 2 do for j to 2 do for k to 2 do
Prelim[i, j, k] := Q[k][i, j];
simplify(Prelim[i, j, k] ); end do end do end do;
#(OPTIONAL PRINTOUT) print(Prelim);
for i to 2 do for j to 2 do for k to 2 do
cyclicPrelim[i, j, k] := Prelim[i, j, k]+Prelim[j, k, i]-Prelim[k, i, j] ;
end do end do end do;
#(OPTIONAL PRINTOUT)  print(cyclicPrelim);
for i to 2 do for j to 2 do for k to 2 do
Gamma[i, j, k] := simplify((1/2)*add(N[i, s]*cyclicPrelim[j, s, k], s = 1 .. 2));
end do end do end do;
# for k from 1 to 2 do
#print(`GAMMA[i,j,k] =` Matrix([[ `%a` , `%a` ],[ `%a` , `%a` ]])` \n`, Gamma[1,1,k], [Gamma[1,2,k], Gamma[2,1,k], Gamma[2,2,k]);
# end do;
#printf('GAMMA[%a,%a,%a] = %a \n', i,j,k, Gamma[i,j,k]);

print([Gamma[1,1,1], Gamma[1,2,1], Gamma[2,1,1], Gamma[2,2,1], Gamma[1,1,2], Gamma[1,2,2], Gamma[2,1,2], Gamma[2,2,2]]);

for i from 1 to 2 do
for j from 1 to 2 do
for k from 1 to 2 do
C[i,j,k]:= apply(Gamma[i,j,k],t);
end do end do end do;
C:=Array(1..2,1..2,1..2,[ [ [ apply(Gamma[1,1,1],t), apply(Gamma[1,2,1],t) ], [ apply(Gamma[1,1,2],t), apply(Gamma[1,2,2],t) ] ], [ [ apply(Gamma[2,1,1],t), apply(Gamma[2,2,1],t) ],  [ apply(Gamma[2,1,2],t), apply(Gamma[2,2,2],t) ] ] ]);
print(C);

end proc;

The differential equation solver:

inits:=[u(0)=1, D(u(t))(0)=1,v(0) = 1, D(v(t))(0)=1];

sys1:= [D[1$2](u(t))+C[1,1,1]*(D(u(t)))^(2)+2*C[1,1,2]*(D(u(t)))*(D(v(t)))+C[1,2,2]*(D(v(t)))^2=0, D[1$2](v(t))+C[2,1,1]*(D(u(t)))^(2)+2*C[2,1,2]*(D(u(t))*D(v(t)))^(2)+C[2,2,2]*(D(v(t)))^2=0];

L:=dsolve({sys1} union {inits});

The error message that comes up is:

"Error, (in unknown) invalid input: op expects 1 or 2 arguments, but received 0"

Any help would be greatly appreciated.

Hi say I have the vector V1.

V1:=Vector([a,b,c,d,e,f,g]):

and function myfun.

how do i use it as the input to the function my fun, by taking away each element in turn?
myfun(V1[2..]);              # 1st element removed
myfun(V1[[1,3..]]);         # 2nd element removed
myfun(V1[[1,2,4..]]);      # 3rd element removed

and so go

is there a more efficient way?

Many thanks,

Hi everybody,

I have never done statistics in Maple.  In a simple calculation, I need to calculate the RMS of 55 numbers.  The average of those numbers is 100484.3 and it is given that the RMS is 1.28 counts.  I have the a list of the 55 numbers.  Since I don't need a demonstration, it would help me a lot if you could tell me how to load the data from a *.txt file (one number per line), and use the appropriate commands to obtaine the result that is only given.

For the moment, I only need the steps to proceed with the calculations and how to do it in Maple.

Thank you very much in advance for your help.

--------------------------------------
Mario Lemelin

Maple 18 Ubuntu 13.10 - 64 bits
Maple 18 Win 7 -  64 bits
messagerie : mario.lemelin@cgocable.ca
téléphone :  (819) 376-0987