E=0   f(E)=1.8  = 1/A+1    A=-0.444    kt is unknown. Hence I try many numbers.

This is my code

plot(1/(-0.444*exp(x/3)+1),x=0..9);

I have a problem.  A is negative. The denominator would be zero.

This is the theory.

http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/disfdx.html#c2

RandomCompositions:= proc(n::posint, k::posint)
local
C,
Compositions:= [seq(C-~1, C= combinat:-composition(n+k, k))],
Rand:= rand(1..nops(Compositions))
;
()-> Compositions[Rand()]
end proc:

R:= RandomCompositions(9,6):
n:= 2^13:
S:= 'R()' $ n:

I want to compile statistics each number in a sequence cannot  occur  over twice.

The sequences that do not fit the rule above must be ommitted.

The statistic is  Fermi-Dirac statistics.

I confused the Bose-Einstein condensation and Fermi-Dirac statistics.

But the theory is right.

RandomCompositions:= proc(n::posint, k::posint)
local
C,
Compositions:= [seq(C-~1, C= combinat:-composition(n+k, k))],
Rand:= rand(1..nops(Compositions))
;
()-> Compositions[Rand()]
end proc:

R:= RandomCompositions(9,6):
n:= 10:
S:= 'R()' $ n;

S := [4, 1, 1, 1, 2, 0], [3, 2, 1, 1, 0, 2], [0, 1, 1, 0, 0, 7], [0, 1, 1, 5, 0, 2], [1, 0, 3, 1, 3, 1],

        [1, 3, 1, 1, 0, 3], [1, 4, 2, 0, 2, 0], [5, 0, 0, 3, 1, 0], [1, 1, 1, 4, 0, 2], [0, 1, 2, 1, 0, 5]

[4, 1, 1, 1, 2, 0] , [1, 1, 1, 4, 0, 2]  and [0, 1, 1, 5, 0, 2] , [0, 1, 2, 1, 0, 5]  are same number 

  but different order.

There are two same sequence. I want to  count  as one, and compile statistics the summation, and 

divide by 8.

the result

0=14/8

1=17/8

2=6/8

...

4=2/8

5=2/8

...

RandomCompositions:= module()
local
Compositions, Rand,
ModuleApply:= proc(n::posint, k::posint)
local C;
Compositions:= [seq(C-~1, C= combinat:-composition(n+k, k))];
Rand:= rand(1..nops(Compositions));
()-> Compositions[Rand()]
end proc
;
end module:
R:= RandomCompositions(8,6):
n:= 3:
S:= 'R()' $ n;
map(lhs=rhs/n, Statistics:-Tally(op~([S])));

[0 = 7/3, 1 = 5/3, 2 = 4/3, 5 = 1/3, 6 = 1/3]

plot([S],x=0..8,style=point);

I have  plot problem .

I want to plot the statistics result,but it runs error.

RandomCompositions:= module()
local
Compositions, Rand,

RandomCompositions:= module()
local
Compositions, Rand,
ModuleApply:= proc(n::posint, k::posint)
local C;
Compositions:= [seq(C-~1, C= combinat:-composition(n+k, k))];
Rand:= rand(1..nops(Compositions));
()-> Compositions[Rand()]
end proc;

end module:
R:= RandomCompositions(8,6):
seq(R(),i=1..10);

[0, 0, 2, 6, 0, 0], [1, 0, 0, 3, 4, 0], [0, 3, 3, 2, 0, 0],[1, 2, 4, 0, 1, 0], [0, 4, 0, 1, 3, 0],

[2, 0, 1, 4, 1, 0],[2, 0, 1, 1, 3, 1], [1, 0, 4, 2, 1, 0], [1, 3, 0, 2, 0, 2],[2, 0, 3, 2, 1, 0]

with(Statistics):
Tally(R());
[0 = 1, 1 = 4, 4 = 1]

I want to count the 0 to 8 respectively summation,and divide by i.

 But the  seq command  R() isn't conform  with Tally command R() .

Thanks.