lcmm (version 1.7.1)

WaldMult: Multivariate Wald Test

Description

This function provides multivariate and univariate Wald tests for combinations of parameters from hlme, lcmm, multlcmm or Jointlcmm models.

Usage

WaldMult(Mod,pos=NULL,contrasts=NULL,name=NULL,value=NULL)

Arguments

Mod

an object of class hlme, lcmm, multlcmm or Jointlcmm

pos

a vector containing the indices in Mod$best of the parameters to test

contrasts

a numeric vector of same length as pos. If NULL (the default), a simultaneous test of the appropriate parameters is realised. If contrasts is specified, the quantity to test is the dot product of pos and contrasts.

name

a character containing the name the user wants to give to the test. By default, the name's test is the null hypothesis.

value

the value(s) to test against. By default, test against 0.

Value

• If contrasts is NULL, the function returns a matrix with 1 row and 2 columns containing the value of the Wald test's statistic and the associated p-value.

  If contrasts is not NULL, the function returns a matrix with 1 row and 4 columns containing the value of the coefficient (dot product of pos and contrasts), his standard deviation, the value of the Wald test's statistic and the associated p-value.