Unanswered Questions

This page lists MaplePrimes questions that have not yet received an answer

Hi,

Maybe someone can give me a nice answer without Maple.

I am given a fourier series:
ln|cosx|=Co - sum( (-1)^k/k * cos2kx,k=1..infinity)
and am asked what this tells me about the chevychev series for ln(u).

 

Thanks

Hi, this question is for Samir Kahn or other maplesoft staff.

Is there a way to use modelica biochem or any other chemical path library into maplesim? Do you plan to integrate this library in future versions of maplesim? Wolfram systemModeler has this library already integrated as does symbiology in matlab. Mr Kahn, I hope that your background in chemical engineering help you push for this new development in maplesim and help this product be even better than the competion. thank you and let me know as soon as possible.

juan

 

Hello,

 

Is it possible to use Maple 15 Student Edition with the same license information and purchase code both on Windows and Ubuntu?

I did a few Windows reinstalls (guess about 3) hence I used the same purchase code to activate the license that many times. Today I tried installing and using Maple 15 on Ubuntu 12.04.3 LTS 32-bit and to my dismay the license manager said, "Not enough activations left on this account." Furthermore, I have exhausted my download links and would like to know how many times Maple 15 can be activated and if the download links can be refreshed?

 

Thanks

I have found the value of t1 and T, but I am unsure of the value. t1 and T in this case is the initialization time at the which the inventory level to zero in Reaches
warehouse. whether possible negative value? is there a lack of proper writing of parameters in this case? so that the output of t1 and T is negative? thanks a lot

> TC := (p*A*((lambda-sigma)*(exp(lambda*t2)-1)+lambda*(exp((lambda-sigma)*T)-exp((lambda-sigma)*t2)))/(lambda*(lambda-sigma))-Ca-A*exp(lambda*t1)*((beta*a2+b2)*(exp(beta*t1)-1)/beta^2-(lambda*a2-b2)*(1-exp(-lambda*t1))/lambda^2)/(beta+lambda)+A*exp(lambda*t1)*b2*t1/(lambda*beta)-W*((alpha*a1+b1)*(1-exp(-alpha*t1))-alpha*b1*t1*exp(-alpha*t1))/alpha^2+A*(exp(lambda*t2)*((a1+b1*t2)*lambda*alpha+b1*(lambda-alpha))-exp(lambda*t1)*(b1*(alpha^2-lambda^2*exp((lambda+alpha)*(t2-t1)))-(a1+b1*t1)*lambda*alpha*(alpha+lambda*exp((lambda+alpha)*(t2-t1))))/(lambda+alpha))/(lambda^2*alpha^2)+Cs*A*exp((lambda-sigma)*t2)*((T-t2)*(lambda-sigma)-exp((T-t2)*(lambda-sigma))+1)/(lambda-sigma)^2-L*A*((exp(lambda*T)-exp(lambda*t2))/lambda-(exp((lambda-sigma)*T)-exp((lambda-sigma)*t2))/(lambda-sigma))-C*(A*(exp((beta+lambda)*t1)-1)/(beta+lambda)+W+A*(exp((lambda-sigma)*T)-exp((lambda-sigma)*t2))/(lambda-sigma)))/T;
>
> TC2 := subs(t2 = (ln(W*(lambda+alpha)/A)+(lambda+alpha)*t1)/(lambda+alpha), TC);
>
> x1 := diff(TC2, t1) = 0;
>
> x2 := diff(TC2, T) = 0;
>
> x3 := evalf(simplify(lhs(eval(subs(A = 200, lambda = 0.3, a2 = 2.4, b2 = 0.01, a1 = 0.9, b1 = 0.01, alpha = 0.01, beta = 0.04, W = 100, Ca = 90, L = 7, C = 10, p = 15, Cs = 3, sigma = 0.25, x1)))));
>
> x4 := evalf(simplify(lhs(eval(subs(A = 200, lambda = 0.3, a2 = 2.4, b2 = 0.01, a1 = 0.9, b1 = 0.01, alpha = 0.01, beta = 0.04, W = 100, Ca = 90, L = 7, C = 10, p = 15, Cs = 3, sigma = 0.25, x2)))));

> x5 := fsolve({x3, x4}, {T, t1});
          x5 := {T = -15.72808468, t1 = -12.55374671}

You have clickable calc. Today I saw in your email that you have clickable physic but in french. Do you have it in english too>?

Thank you

manolo

Hi

I'm using Maple 17 on Windows 8 (64-bit).

I have noticed that when I use the 'spacecurve' command and try to display it with the 'display' command, nothing shows up. I made sure that I used 'with(plots)' and 'with(plottools)', still nothing. However 'plot3d' works fine. I think it has something to do with the version of Java I'm using but I don't know what. Any help is welcome, thx

Specifications of my laptop:

Graphics: NVIDIA Geforce GT 740m

Processor: Intel(R) Core(TM) i7-3630QM (2.40GHz)

Ram: 6,00 GB

OS: Windows 8.1

Dear all,

I am trying to use Maple for Finite Element calculations. I have a 2d setup with linear basis functions and a 2d gaussian kernel that can rotate with respect to the axes. Attached please find the work sheet I am using.

Basis_function:

B := (x1,y1,x,y) -> max(0, 1-abs(x-x1))*max(0, 1-abs(y-y1))

transmissibility function:

t_hat:= (x1,y1,x,y) -> A*exp(-a*(x-x1)^2-2*b*(x-x1)*(y-y1)-c*(y-y1)^2)

where A  and a,b,c are positive constants. a,b,c are calculated based on an angle phi and the two variances of the gaussian function.

I want to calculate the following function for different points (x1,y1) , (x2,y2):

trans := (x1, y1, x2, y2) -> int(int(B(x1, y1, xz, yz)*(int(int(t_hat(xz, yz, xp, yp)*(B(x2, y2, xz, yz)-B(x2, y2, xp, yp)), xp = x2-10*sigma1 .. x2+10*sigma1), yp = y2-10*sigma2 .. y2+10*sigma2)), xz = x1-hx .. x1+hx), yz = y1-hy .. y1+hy);

this integral in the form that is in the work sheet, works well for phi=0 and the results are what I want (numbers that go to zero as we move points 1 and 2 away from each other). for other values for phi it either gives an error (too many levels of recursion) or it returns expressions that seem unreasonable when I evaluate them (they don't go to zero).

for example, it doesn't work for phi = 0.5 at all. for phi = Pi/4 it will calculate some expression,

but as you move away from a point (e.g. trans(0,0,100,100)) the value does not become smaller than a certain value, but they should go to zero.

It seems that what I am trying to do is very sensitive to a,b,c, but actually it shouldn't be so different. I like to avoid exact integration, and just get a number, but I have no idea how to do this numerically. and I don't know how to write the problem in a way that would work for every angle phi.

any ideas?

thanks in advace,2d_maple_primes.mw

with(plots); with(LinearAlgebra); with(ArrayTools)

``

Transmissibility function specifications

alpha := 1;

1

 

4

 

1

 

(1/4)*Pi

(1)

 

a := (1/2)*(cos(phi)/sigma1)^2+(1/2)*(sin(phi)/sigma2)^2;

17/64

 

15/64

 

17/64

 

A = (1/8)/Pi

(2)

 

 

Transmissibility*Kernel

t_hat := proc (x1, y1, x, y) options operator, arrow; A*exp(-a*(x-x1)^2-2*b*(x-x1)*(y-y1)-c*(y-y1)^2) end proc

proc (x1, y1, x, y) options operator, arrow; A*exp(-a*(x-x1)^2-2*b*(x-x1)*(y-y1)-c*(y-y1)^2) end proc

(3)

B := proc (a, b, x, y) options operator, arrow; max(0, 1-abs(x-a))*max(0, 1-abs(y-b)) end proc

proc (a, b, x, y) options operator, arrow; max(0, 1-abs(x-a))*max(0, 1-abs(y-b)) end proc

(4)

trans := proc (x1, y1, x2, y2) options operator, arrow; int(int(B(x1, y1, xz, yz)*(int(int(t_hat(xz, yz, xp, yp)*(B(x2, y2, xz, yz)-B(x2, y2, xp, yp)), xp = x2-10*sigma1 .. x2+10*sigma1), yp = y2-10*sigma2 .. y2+10*sigma2)), xz = x1-hx .. x1+hx), yz = y1-hy .. y1+hy) end proc

proc (x1, y1, x2, y2) options operator, arrow; int(int(B(x1, y1, xz, yz)*(int(int(t_hat(xz, yz, xp, yp)*(B(x2, y2, xz, yz)-B(x2, y2, xp, yp)), xp = x2-10*sigma1 .. x2+10*sigma1), yp = y2-10*sigma2 .. y2+10*sigma2)), xz = x1-hx .. x1+hx), yz = y1-hy .. y1+hy) end proc

(5)

 

#####testing here######

#for phi == 0 the results are what i want, numbers that go to zero as the points go far from each other. for phi != 0 trans returns an expression and the evaluation of that expression doesn't go to zero as we move the points far apart.

NULL

trans(0, 0, 0, 1)

trans(0, 0, 1, 0)

trans(0, 0, 5, 5)

``

This should be zero for any angle

trans(0, 0, 50, 50)

 

 

 

``


Download 2d_maple_primes.mw

Hi,

I open a new subject about Fredholm Integral equation. My code work correctly.

But, I need some modification to get a nice display of the matrix found using
MatA,Vectb := GenerateMatrix(convert(sys3,list),Sol_phi);

such as Sol_phi is my solution that I want to find.

I introduced two function alpha1 and alpha2 in the code  see Equation (9) can I write all the coeficient of my matrix using the two function alpha[1] and alpha[2], it's better to see and read the matrix form.

 

Fred.mw

I have a complicated function that I call on a elements of a list. This function inside calls various other functions and in particular fsolve, which is not thread safe. In order to speed things up I tried using Grid:-Map, but have found a slight drop in performance.

So say a run with map takes 31 seconds, a run with Grid:-Map will take 32 seconds. By looking at the cpu activity, I can tell that only a single core is used at any one time (this is also evident from timing). By looking at the processes, I do see "mserver -gridnode 1/4", etc. present however, so new mserves are certainly spawned - they are just just not used concurrently.

Grid:-NumNodes() gives 4 for my CPU.

Any ideas how to force my code to run on all four nodes??

I am on ubuntu 12.04 x86_64.

thanks.

 ** EDIT **

In case someone finds this useful. Here is a quick-hack that fixes this problem for me.

Look at the current implementation of Grid:-Map with

showstat(Grid:-Map):

Define a new function called say hackMap that is identical to Grid:-Map, except, change the second line from this

     var := `union`(`union`(map(proc (x) op(0,x) end proc,indets(f,function)),indets(f,name)),{'`grid/mapcmd`'});

to this:

     var := {anames('user'), '`grid/mapcmd`'};

now use hackMap as you would Grid:-Map.

It basically forces maple to copy all the 'user' variables over to the new processes. On a machine with 4 nodes i get a ~4 seedup with my particular code.

NOTE: I am not certain that there aren't some side effects as I dont' know all the code behind the scenes, but I seem to get correct results with my particular code.

Hi,

thank for any  help.

I need you help to make a movies ( animation)  according to the index k=1..10.  k is used in Vect_T[k], vector of time to make an animation of the true solution, and it's also used in Matrix(M[..,..,k]), h

True solution:ow can I make a seq of plots for different value of k. 

 

plot3d(True_solution(x,y,Vect_T[k]),x=0..a,y=0..b,axes=boxed,grid= [11,11]);

Analytic solution

plots:-matrixplot(Matrix(M[..,..,k]),axes=boxed,tickmarks= [[1="0", 2=" ", 3=" ", 4=" ", 5=".4", 6=" ", 7=" 0.6", 8=" ", 9=".8", 10=" ", 11="1"],[1="0", 2=" ", 3=" ", 4=" ", 5=".4", 6=" ", 7=" 0.6", 8=" ", 9=".8", 10=" ", 11="1"],default],labels=[x,y,u],axes = boxed);

I tried, this:

S:=seq(plots:-matrixplot(Matrix(M[..,..,i]),labels=[x,y,u],axes = boxed),i=1..10):
plots:-display(S);
 But I get only one figure.

 also,

I tried

BoxTrue:=Null;
for k from 1 to 10 do
BoxTrue:=BoxTrue, plot3d(True_solution(x,y,Vector_time[k]),x=0..a,y=0..b,axes=boxed,grid= [11,11]): od:
display(BoxTrue, insequence=true);
also, no display

 

want to write in maple code

to generate all commutative diagram 

with adjacency matrix

 

however, i only know a -> b, b-> c , a->d , d-> c

google no information about all commutative diagram, 

 

another problem is

would like to enrich theory , however, do not know how to connect property such as equations with diagram

Hi all,

I will use the following dummy example.

with function,f

f:=(xid,yid)->sum(x[i],i=1..xid)*sum(y[i],i=1..yid);

 

and a complicated term, myterm


myterm:=(f(3,4)+f(2,2))*f(1,1):
myterm:=expand(myterm);

 

'if' i have some previous knowledge, or know a bit of the term, i can find the structure by doing this


repar:=[f(1,1),f(2,2),f(3,4)];  # Or with more f(xid,yid) terms

tmp:=seq(repar[i]=ff[i],i=1..3);
simplify(myterm,{tmp});          # This is fine, gives me what i want

 

But, can we go further, and more 'obvious'

 

Given the fucntion f, same as before, and the same 'myterm'

can I have this
restart:
iwant:=(f(3,4)+f(2,2))*f(1,1);  # as a result, straightforward

so I dont have to go back to 'repar' and find that the terms exactly are.

 

Thanks,

 

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];

 

 

 

 

 

 

What is the weak solution integral equation for 

du(x)/dx2 -(1+x2 ) u(x)-1=0

okay so we have to, In the Notation of this question http://www.mapleprimes.com/questions/201278-Fix-A-Syntax-Error-In-My-Simple-Function-please-Help , let f0 be contained in V be any given function and de ne
a sequence (fn) with n contained in (N subscript 0) of functions fn contained in V by

(f subscript 0) := f0  and   fn+1=Afn  for all n contained in (N subscript 0).


prove that this sequence converges pointwise, i.e. that for all   i,j contained in [N]X[N],
(f subscript infinity)(i, j) := (lim n-> infinity  fn(i, j)) exists and that "triangle"(f subscript infintiy) =0
and that
f1 = 0 :

any help would be much appreciated guys <3  

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