Can anyone  produce these diagram?  Please Read the theory in:

   https://en.wikipedia.org/wiki/Logistic_map.

Wikipedia pages that explain bifurcation diagrams and attractors in more elementary contexts.

See the bifurcation diagram in the picture

   https://en.wikipedia.org/wiki/Logistic_map#/media/File:Logistic_Bifurcation_map_High_Resolution.png

 

Download aquestion.mw

Hi. How can I see the code of a graph already plotted.

Thanks

hi
can somebody hep me
i dont know how to add a neww member to an existing set!?
i made an empty set and in my loop for each prime answer i have to add a new memeber to my set but i dont know how!

Is this a correct way to define a piecewise function in which substitution occurs, or are there better ones?

Data := [L=1000, F=1000, E=206000, d0=10];

Diameters := X -> eval(subs(Data, piecewise(x<L/2, d0 ,x<2/3*L, 2*d0 ,x>2/3*L, 1.5*d0)), x=X); 
 

Hello.

Regarding to my previous question I'd like to speed up calculations of the expression. 

restart;
tt := -0.689609e-3; T_c := .242731; mu := .365908; k := 1;
R1 := a*tanh((a^2-mu)/(2*T_c))*ln((2*a^2+2*a*q+q^2-2*mu-(I*2)*Pi*N)/(2*a^2-2*a*q+q^2-2*mu-(I*2)*Pi*N))/q-2;
R2 := Int(R1, a = 0 .. 10000);
R3 := q*ln((-q^2-k^2+mu+I*(2*N*Pi*T_c-(2*m+1)*Pi*T_c)+k*q)/(-q^2-k^2+mu+I*(2*N*Pi*T_c-(2*m+1)*Pi*T_c)-k*q))/(k*(tt+R2));
R4 := Sum(R3, N = -100 .. 100);
m := 1;
R5 := Int(R4, q = 0.1e-2 .. 10000);
R6 := evalf(R5);

Here I have integration procedure inside the expression R3, then the summation over the integer parameter N and then finally the integration again.

Is it possible to speed up calculations of this cumbersome expression? Or actually was I correct to write this simple code?

Thank you in a advance.

K := simplify(C, 'size');
      5                                                  4   
lambda  + (-a__11 - a__33 - a__44 - a__55 - a__22) lambda  + 

  ((a__44 + a__33 + a__22 + a__11) a__55

   + a__44 (a__33 + a__22 + a__11) + (a__33 + a__22) a__11

                                      3                    
   + a__33 a__22 - a__32 a__23) lambda  + (((-a__33 - a__22

   - a__11) a__44 + (-a__33 - a__22) a__11 - a__33 a__22

   + a__32 a__23) a__55

   + ((-a__33 - a__22) a__11 - a__33 a__22 + a__32 a__23) a__44

   + (-a__22 a__33 + a__23 a__32) a__11

                                              2            
   - a__32 (a__13 a__21 + a__24 a__43)) lambda  + ((((a__33

   + a__22) a__11 + a__33 a__22 - a__32 a__23) a__44

   + (a__22 a__33 - a__23 a__32) a__11

   + a__32 (a__13 a__21 + a__24 a__43)) a__55

   + ((a__22 a__33 - a__23 a__32) a__11 + a__13 a__21 a__32) a__44

   + a__32 (a__11 a__43 a__24 - a__21 (a__14 a__43 + a__15 a__53)

  )) lambda + (((-a__22 a__33 + a__23 a__32) a__11

   - a__13 a__21 a__32) a__44

   - a__43 a__32 (a__11 a__24 - a__14 a__21)) a__55

   - a__15 a__21 a__32 (a__43 a__54 - a__44 a__53)

u := [coeffs(K, [lambda], 'l')];
[(((-a__22 a__33 + a__23 a__32) a__11 - a__13 a__21 a__32) a__44

   - a__43 a__32 (a__11 a__24 - a__14 a__21)) a__55

   - a__15 a__21 a__32 (a__43 a__54 - a__44 a__53), 1, 

  -a__11 - a__33 - a__44 - a__55 - a__22, (a__44 + a__33 + a__22

   + a__11) a__55 + a__44 (a__33 + a__22 + a__11)

   + (a__33 + a__22) a__11 + a__33 a__22 - a__32 a__23, ((-a__33

   - a__22 - a__11) a__44 + (-a__33 - a__22) a__11 - a__33 a__22

   + a__32 a__23) a__55

   + ((-a__33 - a__22) a__11 - a__33 a__22 + a__32 a__23) a__44

   + (-a__22 a__33 + a__23 a__32) a__11

   - a__32 (a__13 a__21 + a__24 a__43), (((a__33 + a__22) a__11

   + a__33 a__22 - a__32 a__23) a__44

   + (a__22 a__33 - a__23 a__32) a__11

   + a__32 (a__13 a__21 + a__24 a__43)) a__55

   + ((a__22 a__33 - a__23 a__32) a__11 + a__13 a__21 a__32) a__44

   + a__32 (a__11 a__43 a__24 - a__21 (a__14 a__43 + a__15 a__53)

  )]
u[1] = C__5;
(((-a__22 a__33 + a__23 a__32) a__11 - a__13 a__21 a__32) a__44

   - a__43 a__32 (a__11 a__24 - a__14 a__21)) a__55

   - a__15 a__21 a__32 (a__43 a__54 - a__44 a__53) = C__5
C__1 = u[3];
         C__1 = -a__11 - a__33 - a__44 - a__55 - a__22
C__2 = u[4];
   C__2 = (a__44 + a__33 + a__22 + a__11) a__55

      + a__44 (a__33 + a__22 + a__11) + (a__33 + a__22) a__11

      + a__33 a__22 - a__32 a__23
C__3 = u[5];
C__3 = ((-a__33 - a__22 - a__11) a__44 + (-a__33 - a__22) a__11

   - a__33 a__22 + a__32 a__23) a__55

   + ((-a__33 - a__22) a__11 - a__33 a__22 + a__32 a__23) a__44

   + (-a__22 a__33 + a__23 a__32) a__11

   - a__32 (a__13 a__21 + a__24 a__43)
C__4 = u[6];
C__4 = (((a__33 + a__22) a__11 + a__33 a__22 - a__32 a__23) a__44

   + (a__22 a__33 - a__23 a__32) a__11

   + a__32 (a__13 a__21 + a__24 a__43)) a__55

   + ((a__22 a__33 - a__23 a__32) a__11 + a__13 a__21 a__32) a__44

   + a__32 (a__11 a__43 a__24 - a__21 (a__14 a__43 + a__15 a__53)

  )
 

For some reason, Maple now hangs on the following Schrodinger PDE with initial and boundary conditions.

In Physics version 60, it works OK. No solution is returned, but it does not hang.

But when I updated to latest version of Physics, it hangs. I am not sure which version makes it hangs, I just know Maple does not hang in version 60. So the problem could have happend in any version after 60. I have not attempted to try them all to find out.

PackageTools:-Install("5137472255164416", version = 60, overwrite);
restart;
PackageTools:-IsPackageInstalled("Physics Updates");

              60


x:='x'; t:='t'; y:='y'; hbar:='hbar';f:='f';
pde:=  I* diff(f(x,y,t),t) = -hBar^2/(2*m) * (diff(f(x,y,t),x$2) +  diff(f(x,y,t),y$2)):
ic := f(x, y, 0) = sqrt(2)*(sin(2*Pi*x)*sin(Pi*y) + sin(Pi*x)*sin(3*Pi*y)):
bc := f(0, y, t) = 0,f(1, y, t) = 0, f(x, 1, t) = 0, f(x, 0, t) = 0:
sol:=pdsolve({pde,ic,bc},f(x,y,t));

            ()   #after only few seconds. No hang. good

Now in latest version of Physics

PackageTools:-Install("5137472255164416",  overwrite);
restart;
PackageTools:-IsPackageInstalled("Physics Updates");

                                  "74"

pde:=  I* diff(f(x,y,t),t) = -hBar^2/(2*m) * (diff(f(x,y,t),x$2) +  diff(f(x,y,t),y$2)):
ic := f(x, y, 0) = sqrt(2)*(sin(2*Pi*x)*sin(Pi*y) + sin(Pi*x)*sin(3*Pi*y)):
bc := f(0, y, t) = 0,f(1, y, t) = 0, f(x, 1, t) = 0, f(x, 0, t) = 0:
sol:=pdsolve({pde,ic,bc},f(x,y,t));

#after waiting for long time, had to terminate it
Warning,  computation interrupted

Why does Maple hangs on this PDE now and it did not before?

Using Maple 2018.1 on Linux

I am attempting to make the transition from Mathematica to Maple. I that regard, I would like to know how I would implement something like Mathematica's "Conditioned" in Maple. For example, how would I implement the example given in the diagram shown below involving the Poisson Distribution?

I am trying to solve a diffusion equation with a potential term that has an integral in it. The equation has the following form: 

PDE := diff(g(x, t), t) = diff((beta(x, t)+diff(g(x, t), x)), x), 

with the function beta: 

beta := proc (x, t) options operator, arrow; int(exp(-abs(x-y))*g(y, t), y = -infinity .. +infinity) end proc

The boundary conditions for the function g(x,t) are simply assumed to be a zero-centered Gaussian in space (i.e. in x). So it is unity for x=0 and zero for the outer boundary that we can set as x=L. 

The problem is easily solved if the function beta is not an integral, but in the current form I get the following error: 
*******
Error, (in pdsolve/numeric/process_PDEs) inconsistent dependencies in PDEs: g(x, t) v.s. g(y, t)

*******

So it does not like the dummy variable in the function g.  

I can not write an additional PDE for beta because my Kernel is an exponential so the integral never goes away. Anyone with a way to solve this?

ADDENDUM: I have now copied the scriptPDE_DIFFUSION_INTEGRAL.mw
 

Download PDE_DIFFUSION_INTEGRAL.mw

below. 

Hi everybody,

Written in Maple 2015
restart:
t := table([1=table([a=123]) ]):
save t, MyFile:
restart:
read MyFile:
t[1][a] := 321;

The answer is  t[1][a] =321 (here a double underscore)

Now I read MyFile from Maple 2018
restart:
read MyFile:
t[1][a] := 321;

The result is   (t[1])[a] = 321   (still a double undercsore but the first level is enclosed between parentheses).

For a more hierarchical table, all the entries but the deeper one are between parentheses.

Does this difference in representations mean something about the inner representation of a table ?

Thank you all

Hi everybody,

Maybe it's more a warning than a true question ?

I have written a rather heavy-duty code in Maple 2015. A few years ago I faced strong problems of increases in memory. After some investigations I found there came from a procedure P in which a loop realizes a few tenth of calls to  fsolve.
This same procedure  P was itself called a large number of times.

To try to  fix them I inserted a forget(fsolve, initialize=true) command after the fsolve command.
At the end this didn't prove to be very efficient and I decided to rewrite some part of the code in a more efficient way. Basically the  procedure  P is now called only a few times but its inner loop is executed about 200 hundred times.
This new version of the code no longer presents memory size problems, while being more efficient from a computational time point of view.

Today procedure  P still contains the forget(fsolve, initialize=true) command (I had forgotten to remove it)

Now I keep developping this same code under Maple 2018.
The Maple 2015 and Maple 2018 versions both return the same results, but the procedure  P runs in about 20 times the time it runs in Maple 2015 (40 seconds instead of 2)
This comes from the 200 forget(fsolve, initialize=true) calls which consumme about  38 seconds.

With Maple 2015 these same 200 calls to forget(fsolve, initialize=true) only consumme 0.5 second:

As a cure I remove the forget(fsolve, initialize=true) command, plain and simple.

But maybe this misadventure could reveal an unseen behaviour of Maple 2018 ?

 

Hi

I'm using solve,and i want to quantify the dimensions of the solution spaces of the output. For example

solve([a+b, c+b])

produces a singular 1 dimensional object

solve([a+b, -b^2+d^2])

produces 2 objects with dimension 2

EDIT:
my intuition is that the simplest way of doing this is to create a counter for equations of the form
variable=variable
and to run it on each of the lists that solve might produce- so far this kind of thing is beyond me

 

I am trying to solve an equation with respect to the variable w. However, although there seems to be a solution (see plot indicating a root), Maple produces the wron solution (0, when P = 1/2 and d = 1/10):

Download MaplePrimes_03072018.mw

This pde used to be solved in 2018 as far as I know. Now it gives a strange new error

restart;
interface(showassumed=0);
pde :=  diff(u(x,t),t)+k*diff(u(x,t),x$2)+sin(2*Pi*x/L);
ic  :=  u(x,0)=f(x);
bc  :=  D[1](u)(0,t)=0, D[1](u)(L,t)=0;
sol :=  pdsolve({pde,ic,bc},u(x,t)) assuming L>0,t>0,k>0;

Error, (in assuming) when calling 'dsolve'. Received: 'found differentiated functions with same name but depending on different arguments in the given DE system: {F0_0(L), F0_0(x)}'

I am using  Physics:-Version();     MapleCloud version: 72

Do others get this erorr? Why does it show up now when it worked OK before?

update

Iam running on Linux. Here is screen shot