Get and check input of icfit
get_input_icfit(formula, data, entry)
A list with items
Matrix (number of subjects x 3) containing entry, left and right hand of intervals
Matrix (number of subjects x number of covariates + 1) with design matrix of covariates
A formula object with response of the left of a ~ operator and terms on the right. The response must be a survival object as returned by the `Surv` function, with type either right', 'counting' or 'interval2'
A data frame in which to interpret the variable names in the `formula`
When appropriate, a vector of entry (left truncation) times, or a string indicating the column name in `data` containing entry times; only used if Surv object is of type 'interval2'