Hi all,

I tried to solve the equation f(s) and got the unknow error:

 The related file is attached.

Error.mw

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

If i use expression with function add() it runs normaly, but if I use expression with Threads:-Add (parallel implementation) it causes error "Error, continuation task already created for the current task" or "Kernel connection has been lost"

Expression:

Array(1 .. N,1 .. 1/2*N-NR-1,(i, m) -> evalf(Add(cosArr2[modp(k*i,N)]/kl[k],k = 1 .. NR+m-1)+Add(cosArr2[modp(k*i,N)]*alpha[k],k = NR+m .. 1/2*N)))

What am I doing wrong? Can I use two Add in one evalf?

Birthday_LP.mw

I am attempting to solve the following using C.Loves Logicproblem package. But i do not know how to tell it either/or constaints. being a circular arrangement might also throw a spanner in the works.

Alans Birthday Logic Problem

It is Alan’s birthday and he is having a party. Seven other people will attend: Amy, Brad, Beth, Charles, Debbie, Emily and Frances.

Everyone will sit around the circular dining table. The seating arrangement must meet the following conditions:

• Amy and Alan sit together

• Brad and Beth sit together

• Charles sits next to either Debbie or Emily

• Frances sits next to Debbie

• Amy and Alan do not sit next to either Brad or Beth

• Brad does not sit next to Charles or Frances

• Debbie and Emily do not sit next to each other

• Alan does not sit next to either Debbie or Emily

• Amy does not sit next to Charles

Arrange the guests around the table to meet all of the conditions listed above.

restart:

Vars:= [Name,PN]:

Name:= [Alan,Amy, Brad, Beth, Charles, Debbie, Emily,Frances]:

PN:=[$1..8]:

Cons:= [NextTo(Amy,Alan,PN),NextTo(Brad,Beth,PN),NextTo(Charles,Debbie,PN),NextTo(Charl es,Emily,PN),NextTo(Frances,Debbie,PN),Rel(NotNextTo,Amy,Brad,PN),Rel(NotNextTo, Amy,Beth,PN),Rel(NotNextTo,Alan,Brad,PN),Rel(NotNextTo,Alan,Beth,PN),Rel(NotNext To,Brad,Charles,PN),Rel(NotNextTo,Brad,Frances,PN),

Rel(NotNextTo,Debbie,Emily,PN),Rel(NotNextTo,Alan,Debbie,PN),Rel(NotNextTo,Alan,Emily,PN),

Rel(NotNextTo,Amy,Charles,PN)]:

read "LogicProblem.mpl";

Birthday:= LogicProblem(Vars):

with(Birthday):

Hello,

I would like to solve the differential equation in the following link:

http://www.utdallas.edu/~frensley/technical/nanomes91/node2.html

Without using any explicit discretization. Is it possible to solve this equation with a Maple dsolve comand and some boundary condition option?

I am continuing work with buttons and I wanted to be able to clear graphs with a button.  I understand how to communicate with the button because of other posts by members that have been very helpful.    I want the button to be able to delete the graphs that I have drawn in Plot0.

Is there a way this can happen? Or do my students just need to type a new equation in to the mathematical expression box to plot new functions?

Any help is appeciated. I could not find anything online that I could get to work. I have included the document

Nick

I'm trying to create and populate the Array `A` with a sequence of lower triangular matrices based on the following relation:

A[k+1][i,j] = a (1+k) A[k][i,j] + b ((1+j) A[k][i-1,j] - j A[k][i-1,j-1])

The rows and columns of each matrix are given by i and j; a and b are scalars. The structure of A is not important provided a matrix can be accessed for a given k. The highest k value will not be more than about 100.

The starting matrix for k=1 is

[-1  0]
[ 1 -1]

Any guidance on where to start with setting up the appropriate procedure would be greatly appreciated.

Thanks.

I have a procedure that takes an object, i.e. a module, as an argument. On grounds of the properties of that object, the procedure should return a certain map. But I hit a snag, the gist of which is along the following lines (just an example):

M := module()
   export dim;
   dim := 2;
end module:

F := proc(m::`module`)
   (x::Vector(m:-dim)) -> something
end proc:

My problem is that F(M) produces

rather than

How can I force m:-dim within F to be evaluated?

i want to solve this pde,but i do know how to write my boundary or initial conditons,actually my dependent variables were x and y, i changed x to t,since i faced an error that pde solver needs time=varname , but i could not solve my problem,do anyone know how to insert my boundary conditions ?! please help,thnx
maple.mw

I need a procedure to simplify rational functions r(x,y) = p(x,y)/q(x,y)  where p(x,y) and q(x,y) are polynomials in Z/(2)[x,y].

For example suppose r(x,y) = (1+x+y)/(x^2+x*y+y+1) then mod 2 this reduces to 1/(1+x) since 

            Factor(x^2+x*y+y+1) mod 2 = (1 + x + y) (1 + x)

I wrote a procedure to do this using Factors mod 2, but I wonder if there is a builtin procedure to make such simplifications that might be more efficient.  For now 2 variable is fine, but later I may want more than 2 variables.

Edwin

How can I create a new object from a stanrd, defined in a given metric? For example I want to define an object by convolution of two indices of the Christoffel symbols? I cannot even to see components of such object.

Many thans for an explanation

Leonid

Hi, there i want to basically plot the graph attached. It is basically the graph y= 2x^2 transformed to y = x^2. I can plot them, but how do they get the arrows showing the transformation and the arrows on the axis. Any help would be appreciated.

Thanks

okay so im quite confused, im trying to write a procedure that prints the orbit of a 2x2 matrix through a given list of points.  our arguments should be a a (2x2) matrix, a list L of points represented by 2 vectors, ie (2x1) matrices and a natural number N. Returnvalue : NULL

a side effect should be to 

A^i.L[j] for i = 0 ... N and j = 1 ... nops(L)

thus, an example, if the proc is called P, then 

P(Matrix([[0,-1],[1,0]]),[Matrix([[1],[1]]),Matrix([[1],[0]])],2) 

should plot the points  

(1,1) ,(-1,1) , (-1,-1)  for the 1st point  and 

(1,0)  ,(0,1) , (-1,0) for the second

thanks for any help in advance

Hi, how would you add arrowheads to the x and y-axis to show that they continue.

Thanks 

Composite1:=proc(g,f)
Flist := indets(f): Glist := indets(g): gof:=g:
Subslist1 := [seq( Flist[i]=q, i=1.. nops(Flist))]:
return subs(q=f,subs(Subslist1, gof)): # g(f)
end proc:
#F(g o f) = F(g) o F(f) = F o g o f = (F o g) o (F o f)
Functor := (1/2)*(-y*t2-x*t1-y*t3+sqrt(y^2*t2^2+2*y*t2*x*t1+2*y^2*t2*t3+x^2*t1^2+2*x*t1*y*t3+y^2*t3^2-4*x*t4*y*t9-4*x*t4*y*t8-4*x^2*t4*t7-4*y^2*t5*t9-4*y^2*t5*t8-4*y*t5*x*t7-4*y^2*t6*t9-4*y^2*t6*t8-4*y*t6*x*t7))/(x*t4+y*t5+y*t6);
F1:=x+2;
G1:=3*x+5;
gof:=subs(x=F1, G1);
osys := Composite1(gof, Functor) = Composite1(Composite1(G1, Functor),Composite1(F1, Functor));
sys1 := subs(x=3,subs(y=2, osys));sys2 := subs(x=5,subs(y=1, osys));
sys3 := subs(x=1,subs(y=5, osys));sys4 := subs(x=1,subs(y=2, osys));
sys5 := subs(x=2,subs(y=5, osys));sys6 := subs(x=5,subs(y=2, osys));
sys7 := subs(x=2,subs(y=1, osys));sys8 := subs(x=3,subs(y=5, osys));
sys9 := subs(x=5,subs(y=3, osys));
res:=solve([sys1, sys2, sys3, sys4, sys5, sys6, sys7, sys8, sys9], {t1,t2,t3,t4,t5,t6,t7,t8,t9});
simplify(%);
`~`[lhs](select(evalb, res));

alpha:= (1/2)*(-y*t2-x*t1-y*t3+sqrt(y^2*t2^2+2*y*t2*x*t1+2*y^2*t2*t3+x^2*t1^2+2*x*t1*y*t3+y^2*t3^2-4*x*t4*y*t9-4*x*t4*y*t8-4*x^2*t4*t7-4*y^2*t5*t9-4*y^2*t5*t8-4*y*t5*x*t7-4*y^2*t6*t9-4*y^2*t6*t8-4*y*t6*x*t7))/(x*t4+y*t5+y*t6);
g := -y/x;
f := (-x+sqrt(x^2-x*y-2*y^2))/(2*y+x);
subs(p=f,subs(q=f,subs(x=p,subs(y=q,g))));
g := (1/2)*(-x+sqrt(x^2-4*y*x-4*y^2))/(x+y);
f := x*y;
gof := subs(p=f,subs(q=f,subs(x=p,subs(y=q,g))));
lhsgofoalpha := subs(q= alpha,subs(p=alpha, subs(x=p,subs(y=q,gof))));
foalpha := subs(p= alpha,subs(q=alpha,subs(x=p,subs(y=q,f))));
rhsgofoalpha := subs(x= foalpha,subs(y= foalpha, g));
osys := lhsgofoalpha = rhsgofoalpha;
sys1 := subs(x=3,subs(y=2, osys));
sys2 := subs(x=5,subs(y=1, osys));
sys3 := subs(x=1,subs(y=5, osys));
sys4 := subs(x=1,subs(y=2, osys));
sys5 := subs(x=2,subs(y=5, osys));
sys6 := subs(x=5,subs(y=2, osys));
sys7 := subs(x=2,subs(y=1, osys));
sys8 := subs(x=3,subs(y=5, osys));
sys9 := subs(x=5,subs(y=3, osys));
res:=solve([Re(sys1)=0, Re(sys2) =0, Re(sys3) =0, Re(sys4) =0, Re(sys5) =0, Re(sys6) =0, Re(sys7) =0, Re(sys8) =0, Re(sys9) =0], {t1,t2,t3,t4,t5,t6,t7,t8,t9});