whatmv: Calculate weights for deconvolution of bivariate KDE

Description Usage Arguments Value Author(s) References See Also Examples

Description

Routine to calculate the weights for deconvolution via weighted kernel density estimates for the bivariate case.

Usage

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w.hat.mv(y, Sigma, H, gamma, ...)

Arguments

y

a matrix with two columns containing the observed, contaminated data.

Sigma

the variance-covariance matrix of the contaminating (normal) distribution.

H

the matrix of smoothing parameters to be used for the weighted bivariate kernel density estimate; if missing the bandwidth returned by Hpi(y,) will be used.

gamma

the regularisation parameter to be used; either a scalar or a vector of values from which a suitable value is selected via K-fold cross-validation.

...

optional parameters passed to the cross-validation routine cv.score.mv if K-fold cross-validation is used.

Value

A vector containing the weights; if gamma is chosen by cross-validation, the selected value is returned as an attribute.

Author(s)

Martin L Hazelton m.hazelton@massey.ac.nz

Berwin A Turlach Berwin.Turlach@gmail.com

References

Hazelton, M.L. and Turlach, B.A. (2009). Nonparametric density deconvolution by weighted kernel estimators, Statistics and Computing 19(3): 217–228. http://dx.doi.org/10.1007/s11222-008-9086-7.

See Also

wkde.2d, wkde.contour, Hpi

Examples

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  library(ks)
  Age <- framingham[,2]
  Age.lim.2 <- 56
  SBP1.A <- framingham[Age>=Age.lim.2,3] # SBP, measure 1, Exam 2 
  SBP2.A <- framingham[Age>=Age.lim.2,4] # SBP, measure 2, Exam 2 
  SBP1.B <- framingham[Age>=Age.lim.2,5] # SBP, measure 1, Exam 3 
  SBP2.B <- framingham[Age>=Age.lim.2,6] # SBP, measure 2, Exam 3 
  sigma.fram.A <- sd(SBP1.A-SBP2.A)
  sigma.fram.B <- sd(SBP1.B-SBP2.B)
  Sigma.fram <- diag(c(sigma.fram.A,sigma.fram.B))^2
  SBP.A <- SBP1.A
  SBP.B <- SBP1.B
  SBP.bi <- cbind(SBP.A,SBP.B)
  H.fram <- Hpi(SBP.bi)

  w <-  w.hat.mv(SBP.bi, Sigma.fram, H.fram, gamma = 0.4)
  plot(SBP.bi, cex=w)  

DeconWK documentation built on May 2, 2019, 6:08 p.m.