Calculates the probabilistic weights for the multivariate data.
expectation_mv(data, weights, meu, sigma, prior, num_clusters, tolerance)
(matrix): The input data.
(matrix): The probability weight matrix.
(matrix): The matrix of meu.
(list): The list of sigma (co-variance matrices).
(vector): The vector of priors.
(numeric): The number of clusters.
(numeric): The system epsilon value.
Updated probability weight matrix.