> local `+`;
Error, unable to parse

meet difficulty running script in maple 12

restart;  local `+`;  `+`:=proc(a,b) :-`+`(a^`~2`,b^`~2`) end proc;

Hi all,
I am writing a procedure that I would like to have several outputs. The code is as follows:

Initialize := proc (p, theta, PiV, PiU, n, m)

J := CompJ(PiU, m);

for i to n do

if member(i, V) then

Ai[i] := CompAi(PiU, PiV, i, n, J)

end if

end do

end proc

The function calls other functions previously defined that are not important here. Basically I would like to return the set J and the list Ai, but I am not sure on how to do it. 

Once the procedure returns these elements, I would like to assign them to some variables. I am not sure on how this can be done when a function returns more than one thing.

Thanks in advance for the help
Bests
Manuele 

I have a system of linear differential equations and am trying to solve them using Fourier transforms.

I can reduce the system to a final result (for the variable of interest) in Fourier space as this (note the frequency variable is 'w'):

restart:

with(inttrans):

vout_fourier_num := fourier(phi[3](t), t, w) = 6.63569999999998*10^(-15)*w^2*fourier(V(t), t, w)/(-5.69875218358308*10^(-40)*w^4+(9.19473390627057*10^(-29)*I)*w^3+2.15219369729956*10^(-18)*w^2-(4.14691648617110*10^(-8)*I)*w-700.8);

#the drive can be defined as:
drive:=5.70000000000000*10^(-6)*exp(-3.18877551020408*10^18*(t-2.0*10^(-9))^2)*cos(4.8*10^9*Pi*(t-2.0*10^(-9)))*10^(19/20);

#substitute the drive in - this is not necessary, but it should work!...
vout_fourier_num2:=subs(V(t)=drive, vout_fourier_num);

#now take the inverse... note this gives 0!...
invfourier(vout_fourier_num2, w, t);

the final results calculated is zero. It is wrong... it seems like an accuracy issue, but increasing the digits does not help. I should note that I can calculate the solution directly via dsolve, and get completely reasonable answer.

any ideas how to get the Fourier method to work?

thanks!

hello

this is my program and fsolve for low intensity solve the equations but for high intensity cannot solve why?

this is my code:

ep0 := 1/(4*3.14);

el := 8.54*10^(-2);

hbar := 1;

vf := 1/300;

kb := 1;

tem := 2.586*10^(-2);

ci := 1;

p := 1.458*10^16;

beta := 2;

ai := 7.1*10^(-4);

bi := ai/sqrt(3);

enph := .196;

d := enph/(kb*tem);

n0 := 1/(exp(enph/(kb*tem))-1);

gama := hbar*vf;

intensity:=9000000

w := 7.28;

impurity := 7.2*10^3;

g := hbar*beta/(bi^2*sqrt(2*p*enph));

aa := g^2*(n0+1)/(2*Pi*hbar*gama^2);

bb := g^2*n0/(2*Pi*hbar*gama^2);

cc := 2/(Pi*gama^2);

l := (1*hbar)*w/(2*kb*tem);

u := el^2*intensity/(32*w*hbar^2);

[fsolve({op([((enph*ln(1+exp(c+enph/(kb*tem)))/(kb*tem)-polylog(2, -exp(c))+polylog(2, -exp(c+enph/(kb*tem))))*enph*(kb*tem)^2-(enph^2*ln(1+exp(c+enph/(kb*tem)))/(kb^2*tem^2)+2*enph*polylog(2, -exp(c+enph/(kb*tem)))/(kb*tem)+2*polylog(3, -exp(c))-2*polylog(3, -exp(c+enph/(kb*tem))))*(kb*tem)^3+(-exp(b)*enph*ln(1+exp(c+enph/(kb*tem)))+exp(c+d)*enph*ln(1+exp(b-d+enph/(kb*tem)))+exp(b)*kb*tem*polylog(2, -exp(c))-exp(c+d)*kb*tem*polylog(2, -exp(b-d))-exp(b)*kb*tem*polylog(2, -exp(c+enph/(kb*tem)))+exp(c+d)*kb*tem*polylog(2, -exp(b-d+enph/(kb*tem))))*enph*(kb*tem)^2/((exp(b)-exp(c+d))*kb*tem)+(exp(b)*enph^2*ln(1+exp(c+enph/(kb*tem)))-exp(c+d)*enph^2*ln(1+exp(b-d+enph/(kb*tem)))+2*exp(b)*enph*kb*tem*polylog(2, -exp(c+enph/(kb*tem)))-2*exp(c+d)*enph*kb*tem*polylog(2, -exp(b-d+enph/(kb*tem)))+2*exp(b)*kb^2*tem^2*polylog(3, -exp(c))-2*exp(c+d)*kb^2*tem^2*polylog(3, -exp(b-d))-2*exp(b)*kb^2*tem^2*polylog(3, -exp(c+enph/(kb*tem)))+2*exp(c+d)*kb^2*tem^2*polylog(3, -exp(b-d+enph/(kb*tem))))*(kb*tem)^3/((exp(b)-exp(c+d))*kb^2*tem^2))*bb+u*(1/(1+exp(-l-c))-1/((1+exp(-l-c))*(1+exp(l-b))))-(((1*enph)*(enph-2*kb*tem*ln(1+exp(-b+enph/(kb*tem))))/(2*kb^2*tem^2)+2*kb^2*tem^2*(-polylog(2, -exp(-b+enph/(kb*tem)))+polylog(2, -cosh(b)+sinh(b))))*enph*(kb*tem)^2-(enph^2*(enph-3*kb*tem*ln(1+exp(-b+enph/(kb*tem))))-6*kb^2*tem^2*(enph*polylog(2, -exp(-b+enph/(kb*tem)))+kb*tem*(-polylog(3, -exp(-b+enph/(kb*tem)))+polylog(3, -cosh(b)+sinh(b)))))*(kb*tem)^3/(3*kb^3*tem^3)-(-exp(b)*enph^2+exp(c+d)*enph^2-2*exp(c+d)*enph*kb*tem*ln(1+exp(-b+enph/(kb*tem)))+2*exp(b)*enph*kb*tem*ln(1+exp(-c-d+enph/(kb*tem)))+2*exp(c+d)*kb^2*tem^2*polylog(2, -exp(-b))-2*exp(b)*kb^2*tem^2*polylog(2, -exp(-c-d))-2*exp(c+d)*kb^2*tem^2*polylog(2, -exp(-b+enph/(kb*tem)))+2*exp(b)*kb^2*tem^2*polylog(2, -exp(-c-d+enph/(kb*tem))))*enph*(kb*tem)^2/((2*(-exp(b)+exp(c+d)))*kb^2*tem^2)-(exp(b)*enph^3-exp(c+d)*enph^3+3*exp(c+d)*enph^2*kb*tem*ln(1+exp(-b+enph/(kb*tem)))-3*exp(b)*enph^2*kb*tem*ln(1+exp(-c-d+enph/(kb*tem)))+6*exp(c+d)*enph*kb^2*tem^2*polylog(2, -exp(-b+enph/(kb*tem)))-6*exp(b)*enph*kb^2*tem^2*polylog(2, -exp(-c-d+enph/(kb*tem)))+6*exp(c+d)*kb^3*tem^3*polylog(3, -exp(-b))-6*exp(b)*kb^3*tem^3*polylog(3, -exp(-c-d))-6*exp(c+d)*kb^3*tem^3*polylog(3, -exp(-b+enph/(kb*tem)))+6*exp(b)*kb^3*tem^3*polylog(3, -exp(-c-d+enph/(kb*tem))))*(kb*tem)^3/((3*(-exp(b)+exp(c+d)))*kb^3*tem^3))*aa-u*(1/(1+exp(l-b))-1/((1+exp(-l-c))*(1+exp(l-b)))) = 0, -cc*polylog(2, -exp(b))+cc*polylog(2, -exp(-c))-impurity = 0])}, {op([b, c])})];

thank you.

hi,I want to solve this equation with the following boundary condition numerically by maple:

hello evreybody i have these Error :

restart:with(plots):
M:=765 : m:=587 :I:=76.3*10^3 :Jp:=7.3*10^3 :e:=10.92: F:=0.42: omega:=0.56 :ka:=0.1:kb:=0.1:kc:=0.1: lambda1:=0.1 :lambda2:=0.1:lambda3:=0.1:
Error, illegal use of an object as a name

please help 
thank you !

Is there away to quickly execute a specific section within Maple? I know that I can execute a selection, but that sometimes requires me to select several lines of Maple code and can be tedious and tiresome.

please help me to find an analytical approach to the below equation:

> ode3 := diff(n(t), t)+(1/2)*(-(3.707186000*(0.815e-1*(diff(n(t), t, t))+diff(n(t), t)))/(0.815e-1*(diff(n(t), t))+n(t))^(3/2)-(.1428*(1+0.714e-1*n(t)))*(diff(n(t), t)))/sqrt(7.414372/sqrt(0.815e-1*(diff(n(t), t))+n(t))-(1+0.714e-1*n(t))^2)+n(t)+sqrt(7.414372/sqrt(0.815e-1*(diff(n(t), t))+n(t))-(1+0.714e-1*n(t))^2)-(2.518891688*(1+.3570*n(t)))*sqrt(0.815e-1*(diff(n(t), t))+n(t)) = 0;
                                                                           /
                                                                           |
/ d      \                                 1                               |
|--- n(t)| + ------------------------------------------------------------- |
\ dt     /                                                           (1/2) |
               /           7.414372                                2\      |
             2 |------------------------------- - (1 + 0.0714 n(t)) |      |
               |                          (1/2)                     |      \
               |/       / d      \       \                          |       
               ||0.0815 |--- n(t)| + n(t)|                          |       
               \\       \ dt     /       /                          /       
              /       / d  / d      \\   / d      \\
  3.707186000 |0.0815 |--- |--- n(t)|| + |--- n(t)||
              \       \ dt \ dt     //   \ dt     //
- --------------------------------------------------
                                     (3/2)          
           /       / d      \       \               
           |0.0815 |--- n(t)| + n(t)|               
           \       \ dt     /       /               

                                        \       
                                        |       
                              / d      \|       
   - 0.1428 (1 + 0.0714 n(t)) |--- n(t)|| + n(t)
                              \ dt     /|       
                                        |       
                                        |       
                                        /       

                                                           (1/2)
     /           7.414372                                2\     
   + |------------------------------- - (1 + 0.0714 n(t)) |     
     |                          (1/2)                     |     
     |/       / d      \       \                          |     
     ||0.0815 |--- n(t)| + n(t)|                          |     
     \\       \ dt     /       /                          /     

                                                             (1/2)    
                                   /       / d      \       \         
   - 2.518891688 (1 + 0.3570 n(t)) |0.0815 |--- n(t)| + n(t)|      = 0
                                   \       \ dt     /       /         
> ics := n(0) = 0, (D(n))(0) = 674.5142595;

thanks and regards

louiza

Hello,

I have a easy question I think but blocking for me.

I have a expression g(t):=f(x(t),alpha(t),beta(t))

I give 

x(t):=0.12
alpha(t):=0
beta(t):=0

I would like to evaluate g(t).

And for the moment x(t), alpha(t) and beta(t) aren't replaced by their values.

How can i do in order to have the evaluation of g(t) ?

Thanks a lot for help.

i am using plot command to plot the first vs the second column in the attached file A.txt

it is giving a strange plot. while plotting the first vs second column in kgraph i am getting the correct plot

why is maple giving me a wrong plot 

you can find the two plots and the raw data file A.txt

Download A.txt

Hallo,

Is there a fairly straightforward method for obtaining an array of coordinates from an implicit equation? I have an ellipse defined implicitly (by a horrendously involved expression) and can't figure out how to extract a set of coordinates from an implicitplot. I'm reluctant to use seq and fsolve with a fixed stepsize.

Would be grateful for some insight!

Thanks.

Weirp

Hi Mapleprimers,

I was wondering if there way a way to use restart(); and clear Maple's memory, but protect the memory in a certain variable?  I would like to return the memory to the operating system, but keep a symholic function in memory.

Alternatively, is there a way to save a symbolic function to a file, then reload it at a seperate time?

Hi All. Hope all is well.

Assume that we have partitioned [0,a], into N equidistant subintervals and in each subinterval we have M sets of polynomials of arbitrary form[say b_ij(t)](a.e Taylor series, or Bernstein series,…)

for Example with N=4, M=3 and by Taylor series we have:

now we want to approximate a function, asy f(t), in this interval with following form:

If we have:

(Tau is a constant number)
then: How can  we find L and Z matrices using maple? Is it any way? (or other softwares?)

Regards

Mahmood   Dadkhah

Ph.D Candidate

Applied Mathematics Department

evalf(10.2^20, 50);

evalf((10+1/5)^20, 50);

Where are 50 digits of the first result?

how gr operators work?

I tried to run example given there but it is not working,

where can I get more examples to understand working of Gr operators work?

specially for raychaudhuri equations.