Cumulative distribution function for Gaussian mixture distribution
y = cdf(obj,X)
y = cdf(obj,X) returns a vector y of length n containing the values of the cumulative distribution function (cdf) for the gmdistribution object obj, evaluated at the n-by-d data matrix X, where n is the number of observations and d is the dimension of the data. obj is an object created by gmdistribution or fitgmdist. y(I) is the cdf of observation I.