Normal-gamma Distribution - Definition

Definition

For a pair of random variable, (X,T), suppose that the conditional distribution of X given T is given by

where this mean that the condition distribution is a normal distribution with mean and precision — equivalently, with variance

Suppose also that the marginal distribution of T is given by

where this means that T has a gamma distribution. Here λ, α and β are parameters of the joint distribution.

Then (X,T) has a normal-gamma distribution, and this is denoted by

 (X,T) \sim \mathrm{NormalGamma}(\mu,\lambda,\alpha,\beta) \! .

Read more about this topic:  Normal-gamma Distribution

Famous quotes containing the word definition:

    It is very hard to give a just definition of love. The most we can say of it is this: that in the soul, it is a desire to rule; in the spirit, it is a sympathy; and in the body, it is but a hidden and subtle desire to possess—after many mysteries—what one loves.
    François, Duc De La Rochefoucauld (1613–1680)

    The man who knows governments most completely is he who troubles himself least about a definition which shall give their essence. Enjoying an intimate acquaintance with all their particularities in turn, he would naturally regard an abstract conception in which these were unified as a thing more misleading than enlightening.
    William James (1842–1910)

    ... if, as women, we accept a philosophy of history that asserts that women are by definition assimilated into the male universal, that we can understand our past through a male lens—if we are unaware that women even have a history—we live our lives similarly unanchored, drifting in response to a veering wind of myth and bias.
    Adrienne Rich (b. 1929)