8 lines
162 B
Mathematica
8 lines
162 B
Mathematica
|
function E = entropy(d)
|
||
|
|
if ischar(d), d=abs(d); end;
|
||
|
|
[Y,I,J] = unique(d);
|
||
|
|
H = sparse(J,1,1);
|
||
|
|
p = full(H(H>0))/length(d);
|
||
|
|
E = -sum(p.*log2(p));
|
||
|
|
end;
|