| 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)