probest: Stratified Multivariate Kawaguchi Koch Wang Estimators
In MultNonParam: Multivariate Nonparametric Methods

probest

R Documentation

Stratified Multivariate Kawaguchi Koch Wang Estimators

Description

Function that return the estimators and their variance-covariance matrix calculated with the Kawaguchi - Koch - Wang method.

Usage

probest(ds, resp, grp, str = NULL, covs = NULL, delta = NA, correct = FALSE)

Arguments

`ds`	The data frame to be used.
`resp`	The vector of the response manifest variable. There can be more than one variable. It has to be the name of the variable as a character string.
`grp`	The vector of the variable that divides the population into groups. It has to be the name of the variable as a character string.
`str`	The vector of the variable used for the strata. It has to be the name of the variable as a character string.
`covs`	The covariates to be used in the model. It has to be the name of the variable as a character string.
`delta`	Offeset for covariates.
`correct`	Should the variance estimator be corrected as in Chen and Kolassa?

Details

The function calls a Fortran code to calculate the estimators b and their variance-covariance matrix Vb

Value

A list with components b, the vector of adjusted estimates from the method, and Vb, the corresponding estimated covariance matrix.

References

A. Kawaguchi, G. G. Koch and X. Wang (2012), "Stratified Multivariate Mann-Whitney Estimators for the Comparison of Two Treatments with Randomization Based Covariance Adjustment", Statistics in Biopharmaceutical Research 3 (2) 217-231.

J. E. Kolassa and Y. Seifu (2013), Nonparametric Multivariate Inference on Shift Parameters, Academic Radiology 20 (7), 883-888.

Examples

# Breast cancer data from the MultNonParam package.
data(sotiriou)
attach(sotiriou)
#First simple plot of the data
plot(AGE,TUMOR_SIZE,pch=(recur+1),main="Age and Tumor Size",
  sub="Breast Cancer Recurrence Data",xlab="Age (years)",
  ylab="Tumor Size",col=c("blue","darkolivegreen"))
legend(31,8,legend=c("Not Recurrent","Recurrent"),
  pch=1:2,col=c("blue","darkolivegreen"))
#AGE and TUMOR_SIZE are the response variables, recur is used for the groups,
#TAMOXIFEN_TREATMENT for the stratum and ELSTON.ELLIS_GRADE is a covariate.
po<-probest(sotiriou,c("AGE","TUMOR_SIZE"),"recur",
  "TAMOXIFEN_TREATMENT","ELSTON.ELLIS_GRADE")

MultNonParam documentation built on Aug. 30, 2023, 9:09 a.m.