mv.2sample.est: Multivariate Two Sample Shift Estimates

In MNM: Multivariate Nonparametric Methods. An Approach Based on Spatial Signs and Ranks

Multivariate Two Sample Shift Estimates

Description

Estimates the multivariate shift for different score functions and their asymptotic covariance matrices in the two sample case.

Usage

mv.2sample.est(X, g, score = "identity", stand = "outer", 
               maxiter = 100, eps = 1e-06, na.action = na.fail,
               ...)

Arguments

X	a numeric data frame or matrix.
g	a factor with two levels
score	the score to be used. Possible choices are identity, sign and rank.
stand	the standardization method used. Possible choices are outer and inner.
maxiter	maximum number of iterations. Used only for score = "sign" and score = "rank".
eps	convergence tolerance. Used only for score = "sign" and score = "rank".
na.action	a function which indicates what should happen when the data contain 'NA's. Default is to fail.
...	arguments that can be passed on to functions used for the estimation of location.

Details

This implements the location estimates and their asymptotic covariance matrices as described in chapter 11 of the MNM book. Note that the shift is the parameter for the defference between 'values of level 1 - values of level 2' where the levels are as defined in the factor g.

For the general c sample location case the function mv.l1lm might be used.

Value

A list with class 'mvloc' containing the following components:

location	the location estimate as a vector.
vcov	the asymptotic covariance matrix of the location estimate.
est.name	name of the location estimate.
dname	name of data set for which the location was computed.

Author(s)

Klaus Nordhausen

References

Oja, H. (2010), Multivariate Nonparametric Methods with R, Springer.

Nordhausen, K. and Oja, H. (2011), Multivariate L1 Methods: The Package MNM, Journal of Statistical Software, 43, 1-28.

See Also

spatial.sign, spatial.signrank

Examples

X1<- rmvnorm(50,c(0,0,0))
X2<- rmvnorm(70,c(1,1,2))
X<-rbind(X1,X2)
g<-factor(rep(1:2,c(50,70)))

  est.Hot.X <- mv.2sample.est(X, g)
  est.SS.o.X <- mv.2sample.est(X, g, "s")
  est.SS.i.X <- mv.2sample.est(X, g, "s", "i")
  est.SR.o.X <- mv.2sample.est(X, g, "r")
  est.SR.i.X <- mv.2sample.est(X, g, "r", "i")

  est.SS.o.X
  
  summary(est.SS.o.X)
  
  # plotting
   
  plotMvloc(est.Hot.X, est.SS.i.X, est.SR.i.X)

MNM documentation built on May 29, 2024, 8:49 a.m.