Hello.

I wrote a simple code for the plot of the function:

restart;
Omega := 2*Pi*N; R0 := a*tanh((a^2-mu)/(2*T_c))*ln((2*a^2+2*a*q+q^2-2*mu-I*Omega)/(2*a^2-2*a*q+q^2-2*mu-I*Omega))/q-2;                      
T_c := 0.169064e-1; mu := .869262; N := 10;
R1 := int(R0, a = 0.1e-3 .. 100);    
R2 := evalf(abs(R1));
plot(R2, q = 0.1e-2 .. 10);

If the parameter N is not equal to zero then after near one hour calculations I got the desired plot. But for N=0 I have an error

Error, (in signum) too many levels of recursion

I searched this error on this site but I can't find anything relevant for this problem.

Thank you in advance for the help.

Hello everybody.

Maybe I'm so lucky but I found again the problem connected with "Kernel connection lost"; error (see one of my previous post regarding this ). But now I used Intel-based processor.

Here the simple code of my program:

restart;
R0 := exp((2*Pi*I)*n^2*z);
R1 := sum(R0, n = -infinity .. infinity);
R1 := abs(R1)^2;
R2 := exp((2*Pi*I)*(n+1/2)^2*z);
R2 := evalf(sum(R2, n = -infinity .. infinity));
R2 := abs(R2)^2;
R := evalf(sqrt(Im(d))*(R1+R2));
plot(R, k = 1 .. 10);

After this I got message from Windows 7 (64 bit) that mserver.exe has stopped and then above mentioned error with Kernel connection lost. Anybody knows what is the problem?

P.S. Maple 17 (64 bit).

Hello.

I'd like to plot two coupled functions x=x(t) and y=y(t) given by expression R0 and R1 (see below) for the interval t=0.001..0.999 and then after that extract tha data from the graphs for functions x(t) and y(t).

How can I do that in easiest way?

I will appreciate you.

Hello everybody.

I'd like to share an observation about the integration of the Jacobi elliptic functions, in particularly the elliptic sine sn(x,k).

It's correct answer. But when I make the integration of the expression

according to the Handbook of Elliptic Integrals for Engineers and Scientists we have slightly another result

What is the difference?

Regarding my recent question http://www.mapleprimes.com/questions/221909-How-To-Extract-Data-From-Implicit-Function I would like to share an interesting observation. Here the code of the program:

restart;
R0 := ln(y)+Re(Psi(1/2+(2*(p^2+(1/2)*sqrt(2*I+4*ksi_fs^2*p^2)*tanh(sqrt(2*I+4*ksi_fs^2*p^2)*x)/(tau+0.5e-2*a)))/y))+gamma+2*ln(2)
tau:= 10.000:ksi_fs:=10:p:=0.037:
R0p:= unapply(R0, [a,x]):
R0f:= proc(a,x)
local r:= fsolve(R0p(a,x), y= 0..1);
   `if`(r::float, r, Float(undefined))
end proc:
M:= Matrix(
   (100,100),
   (i,j)-> R0f(i, 1 + (j-1)*(0.5-0)/(100-1)),
   datatype= float[8]
);

After approximately 2 hours of calculations I get a message window

But I repeat this calculations on another computer with the same Windows 7 64 bit and Maple 17 I don't get such error and I obtain desired data.

So can Maple be sensitive to the hardware?