# Calculate entropy for a set of data

Hi;

I am not really a maths person and I have a question regarding shannon entropy. I have different datasets which only consists of three letter(I,N,M) such as : dataset1: {I,I,N,M,I,I} dataset2: {I,I,I,M,I,I,N,M},...

each element in each dataset has a weight which is calculated using a function F(x). For each dataset I like to calculate the entropy using the weight(F(x)).

Now I have two questions; 1) How can I calculate a weighted entropy? 2) Is it possible to convert the F(X) to probabilities so I can use them as probability when calculating the entropy?