entropy, joint entropy and conditional entropy function for n variables

entropy, joint entropy for any number of variables and the conditional entropy

for entropy
H = entropy(S)
this command will evaluate the entropy of S, S should be row matrix
H = entropy([X;Y;Z])
this command will find the joint entropy for the 3 variables
H = entropy([X,Y],[Z,W])
this will find H(X,Y/Z,W).. you can use it for any combination of joint entropies

Please validate this function before using it