Maple Questions and Posts

These are Posts and Questions associated with the product, Maple

Hi everyone,

I have a functional "L" which I want to solve Euler-Lagrange for it and then extermise that functionalexfun.mw by its equation of motions. I know the result must be same to a function like "A" but I cant obtain that. "a", "b" and "s" are constants and not important, I insist more on the shape of "A"

 

Thanks a lot

i am new user in maple .i want to calculate eigenvalues of a symmetrix matrix to find max or min value but i usually face a error code ' (in simpl/max) complex argument to max/min'

i know that a symmetrix matrix have real eigenvalues.

for example:
restart:with(LinearAlgebra):with(GraphTheory):interface(rtablesize=infinity):
SeidelMatrix:=proc(G::Graph) local J,B,A,S;
J:=Matrix(1..NumberOfVertices(G),1..NumberOfVertices(G),shape=constant[1]):
B:=IdentityMatrix(NumberOfVertices(G)):
A:=AdjacencyMatrix(G):
S:=J-B-MatrixScalarMultiply(A,2):
convert(S,Matrix,shape=symmetric,datatype=float):
return S:
end proc:
E:=sort(eval(Eigenvalues(SeidelMatrix(CycleGraph(7)),output='list'))):
(min,max)(E);
Error, (in simpl/min) complex argument to max/min: (1/3)*(-28+(84*I)*3^(1/2))^(1/3)+(28/3)/(-28+(84*I)*3^(1/2))^(1/3)-1/3
 

 

I am trying to evaluate the following summation which gives the result 0. But I think answer is not correct.
 

restart; x := 0; evalf(Sum(Sum(x^(q-p), p = 0 .. q), q = 0 .. 10))

0.

(1)

``


 

Download zero.mw

is it possible to change ODE to PDE?

the ODE has diff(a(t),t) and diff(b(t),t)

how to convert to diff(t, a), diff(t, b) ?

Is there a built-in function in Maple 2015 that identifies and prints prime numbers in a specified integer range?

I've developed a framework in Maple for playing with cyclic division algebras. I have methods for multiplication and passing to and from:

The standard basis over the base field in terms of x^i*y^j and:
The standard matrix basis for the central simple algebra when taking coefficients in the splitting field.

I have it done in the case of degree 7, but could generalise it to any prime degree if this is of use to anyone.

Hi

How can I write and solve a dirac_delta function in maple, for example in below equations:

F[0]:=0;
F[1]:=a;
F[2]:=b;

eq1:=sum((k-m+2)*(k-m+1)*F[k-m+2]*Dirac[m-1], m = 0 .. k);

eq2:=(k+1)*F[k+1]-Dirac[k];

for k from 0 to 10 do
F[k+3]:=solve(F[k+3]=(eq1+eq2)/((k+3)*(k+2)*(k+1)),F[k+3]);
end do;

Hi everybody,

I'm kind of new to Maple and i'm trying to solve a system of trigonometric equations inequality as follow:

f:= {((2*a*sin(S)*cos(S)^(2)))/(1-sin(S)^(3))<1,90> S>-90,a>1};

solve(f,{a,S});
Error, (in PiecewiseTools:-Convert) unable to convert

 

How can I solve the system?

Thanks a lot.

Since I am a very recent Maple user, I do not know why I obtained a wrong answer with the following two comands:

Exp:= Psi(rho(x,t),theta(x,t));
                  Psi(rho(x, t), theta(x, t))
Exp1:= diff(Exp,t);
     / d           \                                  
     |--- rho(x, t)| D[1](Psi)(rho(x, t), theta(x, t))
     \ dt          /                                  

          / d             \                                
    + |--- theta(x, t)| Psi(rho(x, t) + 1, theta(x, t))
          \ dt            /                                
 

Can someone, please, help me?

Thank you.

 

The purpose of this post is to review how well-designed Maple 2017 GUI is for a Microsoft surface pro 4 tablet touch screen with windows 10 pro (64-bit) and to determine the performance of Maple 2017 on my tablet which has a m3 CPU with a 0.9 GHZ base frequency and 4 GB RAM.

First, my experience is that 4 GB of RAM is far from enough. Under heavy load I have had problems before on other software with 4 GB of RAM. 68 % of my RAM and 41% of the CPU is already gone by simply running Maple and my web browser at the same time before I have even instructed Maple to do any calculations.

 

I think a tablet with at least 8 GB of RAM would be preferred. If you only want to use Maple as an expensive calculator then you would most likely not even need 4 GB of RAM. I find that the surface pro 4 to be overpriced for the hardware it provides. I think eve windows 10 tablet http://eve-tech.com/ with up to 16 GB of RAM and with a much cheaper price looks much more promising than the Microsoft surface pro 4. When I use the surface pro 4 with word 2016 and the reference manager zotero word plugin I sometime notice a trailing line when I sweep up or down in a document with a lot of references which I suspect is because of the low amount of RAM. When I played with Maple 2017 on my surface pro I noticed the same trailing line which again indicates to me that there is not enough RAM. However, I am not certain that low RAM is the cause of such problem.  

Secondly, I managed to increase the size of the Maple icons under the File, Edit etc. menu so now they have a perfect size for a touch screen tablet. Very cool!

 

However, as you can see words in the text menu File, Edit etc. are way too small for a touch screen tablet. There is a lot of room to the right so the words could easily be increased in size. I am also a missing a menu item called maplet where you can attach your own maplets for easy access. It appears that Maple 2017 GUI has not been designed with a touch screen tablet in mind. I wish the words in the text menu File, Edit etc. would have increased when I increased the size of the icons. The text and icons in the sidebar are also way too small for a touch screen tablet. The name of the open tabs is also to small and x that you tap on to close the worksheet is also to small. It is almost impossible to close a worksheet because the x is so small. 

I thinks there are ways in windows 10 to increase the text size in the menus but I have only been able to increase the text size and icon size for all software at the same time. Since, Maple is more or less the only software that I have where the menu text is too small this is not an optimal solution.   

The table of content for Maple help files also has too small text as seen in the below picture. However, the biggest problem is not the small words it is the row spacing of the table of content. Some of the words appear almost to be on top of each other. I think the row spacing need to be increased. The text within the help files itself displays beautifully and is in the perfect size.   

 

Another problem is that when you swipe up or down on the touch screen you dont go up or down in the maple document. You just highlight text as seen in the picture below. This needs to be fixed. Highlighting should be done by a long tap on the screen as in word 2017 on a touch screen devices.

 

 

The norm today might be to use Maple on a desktop computer or on a laptop but I am convinced that in the future touch screen tablet will become more and more powerful making them an excellent computers to run Maple on because they are so light and portable. I think Maplesoft must have this in mind when they design the GUI.

Now to test the performance of Maple 2017 on my tablet I decided to generate 1 000 000 random number and see how long it takes. Since I dont have a benchmark it becomes very hard to comment on how fast maple 2017 is on my tablet but I am hoping that someone can run the same code on their machine and comment on this post so we can get a benchmark.        

time(rand()$1000000)

Maple 2017 claims that running such code took about 50 seconds on my tablet however when I timed it with a stop watch it only took around 30 seconds hence I am a bit confused as to where the 20 seconds difference comes from?  

 

I am using Maple to model Gaussian Wave Packets and the do loop creates an array of plots. I want to animate these plots to show the movement of the wave packet and was wondering if there is a way to animate the array or perhaps another way to produce the animation. 

how to add two algebaric equations? I have two equation (1) and (2). i simply wrote (1) + (2) instead of adding the eqautions i got result is 3. i think there is some mistake of writng text for calling equation that was in bold. 

adding_two_equations.mw

I am trying to evaluate the following triple integral but it takes much time so i kill the job.


 

restart; R := 5; KK := proc (theta) options operator, arrow; evalf(int(int(int(1/(R*sin(theta)^2+(R*cos(theta)+Z)^2+(2*R*k.sin(theta))*cos(p))^2, p = 0 .. 2*Pi), Z = 0 .. 60), k = 1 .. 10, numeric)) end proc; evalf(KK((1/6)*Pi))

Warning,  computation interrupted

 

``


 

Download int_maple_prime2.mw

with(DEtools, buildsym, equinv, symtest):
ans := dsolve([eq2,eq3,eq4], Lie);
Error, (in dsolve) too many arguments; some or all of the following are wrong: [{a(t), b(t), c(t)}, Lie]
 
ans := dsolve([eq2+eq3+eq4 = exp(t)], Lie);
Error, (in PDEtools/sdsolve) too many arguments; some or all of the following are wrong: [{a(t), b(t), c(t)}, Lie]
 
ans := dsolve([eq2,eq3,eq4]);
sym2 := buildsym(ans);
Error, (in buildsym) invalid input: `ODEtools/buildsym` expects its 1st argument, sol, to be of type {algebraic, algebraic = algebraic}, but received [{c(t) = ...}, {b(t) = ...}, {a(t) = ...)}]
 
 
PDEtools[declare](a(t), b(t), c(t), prime = t):
symgen(eq2+eq3+eq4=0);
                       a(t) will now be displayed as a
                       b(t) will now be displayed as b
                       c(t) will now be displayed as c
   derivatives with respect to t of functions of one variable will now be
      displayed with 'symgen(....)'
 
 
update
if it can not do for 3 function a(t),b(t),c(t) system of differential equations
then
 
i change to use
eq2 := subs(b(t)=a(t),subs(c(t)=a(t),eq2));
eq3 := subs(b(t)=a(t),subs(c(t)=a(t),eq3));
eq4 := subs(b(t)=a(t),subs(c(t)=a(t),eq4));
 
with(DEtools, buildsym, equinv, symtest):
ans := dsolve(eq2 = 0, Lie);
buildsym(ans[1], a(t));
buildsym(ans[2], a(t));
buildsym(ans[3], a(t));
 
there are 3 answers, can i use one of it to recover the equation eq2 or  eq3 or eq4?
 
ans := dsolve(eq3=0, Lie);
buildsym(ans[1], a(t));
sym2 := buildsym(ans[2], a(t));
buildsym(ans[3], a(t));

sym := [_xi=rhs(sym2[2]),_eta=rhs(sym2[1])];
ODE := equinv(sym, a(t));
eq3 - ODE;
sym := [_xi=rhs(sym2[1]),_eta=rhs(sym2[2])];
ODE := equinv(sym, a(t));
eq3 - ODE;
but ODE is not equal to original eq3
ans := dsolve(eq4=0, Lie);
buildsym(ans[1], a(t));
buildsym(ans[2], a(t));
 
ans := dsolve(eq2+eq3+eq4=0, Lie);
sym := buildsym(ans[1], a(t));
ODE := equinv(sym, a(t));
eq2+eq3+eq4 - ODE;
sym := buildsym(ans[2], a(t));
ODE := equinv(sym, a(t));
eq2+eq3+eq4 - ODE;
sym := buildsym(ans[3], a(t));
ODE := equinv(sym, a(t));
simplify(eq2+eq3+eq4 - - ODE);
 
can not recover the original result

Maple newbie here.

I do not understand why algsubs do not replace the symbol in the denominator in the following example, but does replace it in the numerator. This is on Maple 2017 on windows 7

Here is the expression

sol := u(x, t) = Sum((2*cos((1/2)*Pi*_Z1)+
       2+4*(-1)^(1+_Z1))*sin(Pi*_Z1*x/L)*
       exp(-k*Pi^2*_Z1^2*t/L^2)/(Pi*_Z1), 
       _Z1 = 1 .. infinity);

I wanted to replace _Z1  with n

But algsubs will not replace _Z1 in the denominator as seen in this screen shot but subs does:

 

 

From help, my impression is that algsubs is superset of subs. Only case where algsubs will not do what subs does is, according to help:

The algsubs command goes recursively through the expression . Unlike the subs command it does not substitute inside indexed names, and function calls are applied to the result of a substitution

 

But There is no indexed names here? 

Can someone please explain why algsubs fails to do the substitution in the denominator in this example?

 

 

 

 

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