How is mutual information measured in probability theory?

How is mutual information measured in probability theory?

In probability theoryand information theory, the mutual information(MI) of two random variablesis a measure of the mutual dependencebetween the two variables. More specifically, it quantifies the “amount of information” (in unitssuch as shannons, commonly called bits) obtained about one random variable through observing the other random variable.

How does mutual information quantize the amount of information?

More specifically, it quantifies the ” amount of information ” (in units such as shannons ( bits ), nats or hartleys) obtained about one random variable through observing the other random variable.

How is mutual information used in signal processing?

Mutual information is also used in the area of signal processing as a measure of similarity between two signals. For example, FMI metric [17] is an image fusion performance measure that makes use of mutual information in order to measure the amount of information that the fused image contains about the source images.

How is mutual information different from correlation coefficient?

Unlike correlation coefficients, such as the product moment correlation coefficient, mutual information contains information about all dependence—linear and nonlinear—and not just linear dependence as the correlation coefficient measures.

How is mutual information related to entropy of a random variable?

The concept of mutual information is intimately linked to that of entropy of a random variable, a fundamental notion in information theory that quantifies the expected “amount of information” held in a random variable.

Which is a binomial random variable in pointwise mutual information?

The random variable Y would be: “returns of SPY is below it’s 5% quantile”, so two binomial random variables. Now, based on the pointwise mutual information formula we compute the PMI measure: The PMI measure is about -1.65. What (the hell) does that mean? Pointwise mutual information measure is not confined to the [0,1] range.

Which is the best definition of mutual information?

1 2 + 1 2 + 1 2 + 0 (16) = 3 2 : (17) 3 Mutual Information. Mutual information is a quantity that measures a relationship between two random variables that are sampled simultaneously. In particular, it measures how much information is communicated, on average, in one random variable about another.

How to calculate mutual information between two variables?

Definition The mutual information between two discreet random variables X,Y jointly distributed according to p(x,y) is given by I(X;Y) = X x,y p(x,y)log p(x,y) p(x)p(y) (24) = H(X)−H(X|Y) = H(Y)−H(Y|X) = H(X)+H(Y)−H(X,Y). (25) 4