raschmix-methods
Methods for raschmix Objects
Methods for raschmix-class objects.
Usage
# S4 method for raschmix
summary(object, eps = 1e-4, ...)# S4 method for raschmix
parameters(object,
which = c("model", "item", "score", "concomitant"),
difficulty = TRUE, component = NULL, simplify = TRUE)
# S4 method for raschmix
worth(object, difficulty = TRUE, component = NULL)
# S4 method for raschmix
itempar(object, ref = NULL, alias = TRUE, ...)
scoreProbs(object, component = NULL, simplify = TRUE)
Arguments
- object
An object of class
"raschmix".- eps
Probabilities below this threshold are treated as zero in the summary method.
- which
Indicates which type of parameters are used.
modelrefers to both item and score parameters,itemandscoreto their corresponding parameters separately. The parameters of the concomitant model are accessed throughconcomitant.- difficulty
Indicates whether item difficulty (default) or easiness parameters are used.
- component
Indicates which components are returned. Default is all components.
- ref
a vector of labels or position indices of item parameters or a contrast matrix which should be used as restriction/for normalization. If 'NULL' (the default), all items are used (sum zero restriction).
- alias
logical. If 'TRUE' (the default), the aliased parameter is included in the return vector. If 'FALSE', it is removed. If the restriction given in 'ref' depends on several parameters, the first parameter of the restriction specified is (arbitrarily) chosen to be removed if 'alias' is 'FALSE'.
- simplify
Should the result be simplified if possible?
- ...
Currently not used.
Details
worth transforms the item parameters so that the sum over all
item parameters (within each component) is zero.
itempar allows for the flexible specification of the
restriction applied to the item parameters.
scoreProbs does not include any aliased parameters if a certain
raw score is not present in the data.