Tente isto,

d<-data.frame(x=1:10, y=rep(c(FALSE,TRUE),c(4,6)))
d
glm(y~x, data=d, family=binomial)

keepWarnings <- function(expr) {
    localWarnings <- list()
    value <- withCallingHandlers(expr,
                     warning = function(w) {
                         localWarnings[[length(localWarnings)+1]] <<- w
                         invokeRestart("muffleWarning")
                     })
    list(value=value, warnings=localWarnings)
}

z <- keepWarnings(glm(y~x, data=d, family=binomial))
z
z$value

(S,f,P)

Allaman

\begin{signature}

<<>>=

Prof. Dr. Ivan Bezerra Allaman

Universidade Estadual de Santa Cruz

Departamento de Cięncias Exatas e Tecnológicas

Ilhéus/BA - Brasil

Fone: +55 73 3680-5596

E-mail: ivanalaman@yahoo.com.br/ivanalaman@gmail.com

\end{signature}