made.density: Minimum Approximate Distance Estimate of Density Function...

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made.densityR Documentation

Minimum Approximate Distance Estimate of Density Function with an optimal model degree

Description

Minimum Approximate Distance Estimate of Density Function with an optimal model degree

Usage

made.density(
  x,
  M0 = 1L,
  M,
  search = TRUE,
  interval = NULL,
  mar.deg = TRUE,
  method = c("qp", "em"),
  controls = mable.ctrl(),
  progress = TRUE
)

Arguments

x

an n x d matrix or data.frame of multivariate sample of size n

M0

a positive integer or a vector of d positive integers specify starting candidate degrees for searching optimal degrees.

M

a positive integer or a vector of d positive integers specify the maximum candidate or the given model degrees for the joint density.

search

logical, whether to search optimal degrees between M0 and M or not but use M as the given model degrees for the joint density.

interval

a vector of two endpoints or a 2 x d matrix, each column containing the endpoints of support/truncation interval for each marginal density. If missing, the i-th column is assigned as c(min(x[,i]), max(x[,i])).

mar.deg

logical, if TRUE, the optimal degrees are selected based on marginal data, otherwise, the optimal degrees are chosen the joint data. See details.

method

method for finding minimum distance estimate. "em": EM like method;

controls

Object of class mable.ctrl() specifying iteration limit and the convergence criterion eps. Default is mable.ctrl. See Details.

progress

if TRUE a text progressbar is displayed

Details

A d-variate cdf F on a hyperrectangle [a, b] =[a_1, b_1] \times \cdots \times [a_d, b_d] can be approximated by a mixture of d-variate beta cdfs on [a, b], \beta_{mj}(x) = \prod_{i=1}^dB_{m_i,j_i}[(x_i-a_i)/(b_i-a_i)], with proportion p(j_1, \ldots, j_d), 0 \le j_i \le m_i, i = 1, \ldots, d. With a given model degree m, the parameters p, the mixing proportions of the beta distribution, are calculated as the minimizer of the approximate L_2 distance between the empirical distribution and the Bernstein polynomial model. The quadratic programming with linear constraints is used to solve the problem. If search=TRUE then the model degrees are chosen using a method of change-point based on the marginal data if mar.deg=TRUE or the joint data if mar.deg=FALSE. If search=FALSE, then the model degree is specified by M.

Value

An invisible mable object with components

  • m the given model degree(s)

  • p the estimated vector of mixture proportions with the given optimal degree(s) m

  • interval support/truncation interval [a, b]

  • D the minimum distance at degree m

  • convergence An integer code. 0 indicates successful completion(the EM iteration is convergent). 1 indicates that the iteration limit maxit had been reached in the EM iteration;


mable documentation built on Oct. 1, 2024, 9:06 a.m.