High-density multivariate reference region

The paper considers the principles of construction of multivariate reference regions. An original method of construction of a region on the basis of areas of high density of points and approximation of data distribution with a mixture of normal distributions is suggested. To estimate the threshold for the probability density, the bootstrap method is used. As an experiment, the paper considers the problem of description and use of the reference region for predicting the type of urinary stones. Real data treatment demonstrated the benefits of the proposed solutions.