condGEE: condGEE

In condGEE: Parameter Estimation in Conditional GEE for Recurrent Event Gap Times

condGEE

Description

Solves for the mean parameters (theta), the variance parameter (σ^2), and their asymptotic variance in a conditional GEE for recurrent event gap times, as described by Clement, D. Y. and Strawderman, R. L. (2009)

Usage

condGEE(
  data,
  start,
  mu.fn = MU,
  mu.d = MU.d,
  var.fn = V,
  k1 = K1.norm,
  k2 = K2.norm,
  robust = TRUE,
  asymp.var = TRUE,
  maxiter = 100,
  rtol = 1e-06,
  atol = 1e-08,
  ctol = 1e-08,
  useFortran = TRUE
)

Arguments

data	matrix of data with one row for each gap time; the first column should be a subject ID, the second column the gap time, the third column a completeness indicator equal to 1 if the gap time is complete and 0 if the gap time is censored, and the remaining columns the covariates for use in the mean and variance functions
start	vector containing initial guesses for the unknown parameter vector
mu.fn	the specification for the mean of the gap time; the default is a linear combination of the covariates; the function should take two arguments (theta, and a matrix of covariates with each row corresponding to one gap time) and it should return a vector of means
mu.d	the derivative of mu.fn with respect to the parameter vector; the default corresponds to a linear mean function
var.fn	the specification for V^2, where the variance of the gap time is σ^2 V^2; the default is a vector of ones; the function should take two arguments (theta, and a matrix of covariates with each row corresponding to one gap time) and it should return a vector of variances
k1	the function to solve for the conditional mean length of the censored gap times; its sole argument should be the vector of standardized (i.e.\ (Y-μ)/(σ V)) censored gap times; the default assumes the standardized censored gap times follow a standard normal distribution, but K1.t3 and K1.exp are also provided in the package - they assume a standardized t with 3 degrees of freedom and an exponential with mean 0 and variance 1 respectively
k2	the function to solve for the conditional mean length of the square of the censored gap times; its sole argument should be the vector of standardized (i.e.\ (Y-μ)/(σ V)) censored gap times; the default assumes the standardized censored gap times follow a standard normal distribution, but K2.t3 and K2.exp are also provided in the package - they assume a standardized t with 3 degrees of freedom and an exponential with mean 0 and variance 1 respectively
robust	logical, if FALSE, the mean and variance parameters are solved for simultaneously, increasing efficiency, but decreasing the leeway to misguess start and still find the root of the GEE
asymp.var	logical, if FALSE, the function returns NULL for the asymptotic variance matrix
maxiter	see multiroot; maximal number of iterations allowed
rtol	see multiroot; relative error tolerance
atol	see multiroot; absolute error tolerance
ctol	see multiroot; if between two iterations, the maximal change in the variable values is less than this amount, then it is assumed that the root is found
useFortran	see multiroot; logical, if FALSE, then an R implementation of Newton-Raphson is used

Value

conditional expectation

Author(s)

David Clement

condGEE documentation built on May 24, 2022, 1:06 a.m.