rhoMLogit {bcROCsurface} | R Documentation |
rhoMLogit
is used to fit multinomial logistic models to the disease process in the verified subjects.
rhoMLogit(formula, data, test = FALSE, maxit = 500, trace = FALSE)
formula |
an object of class "formula": a symbolic description of the model to be fitted. |
data |
an optional data frame containing the variables in the model. |
test |
a logical value indicating whether p-values of the regression coefficients should be returned. Default |
maxit |
maximum number of iterations. Default 500. |
trace |
switch for tracing estimation process. Default |
In the formula, the response must be a result of preDATA
, a factor with three levels, say 1, 2, 3. These levels correspond to three classes of disease status, e.g., non-dieseased, intermediate, diseased. The last class (class 3) is considered as the reference level in multinomal logistic model. In presence of verification bias, the missing (NA
) values correspond to non verified subjects.
rhoMLogit
returns a list containing the following components:
coeff |
a vector of estimated coefficients. |
values |
fitted values of the model. |
Hess |
the Hessian of the measure of fit at the estimated coefficients. |
D |
the disease status vector used. |
X |
a design model matrix. |
formula |
the fomular supplied. |
To Duc, K., Chiogna, M. and Adimari, G. (2016) Bias-corrected methods for estimating the receiver operating characteristic surface of continuous diagnostic tests. Electronic Journal of Statistics, 10, 3063-3113.
data(EOC) Dna <- preDATA(EOC$D, EOC$CA125) Dfact.na <- Dna$D out <- rhoMLogit(Dfact.na ~ CA125 + CA153 + Age, data = EOC, test = TRUE, trace = TRUE)