Coercing Item Response Data
Coercing "itemresp" data objects to other classes.
## S3 method for class 'itemresp' as.list(x, items = NULL, mscale = TRUE, df = FALSE, ...)
x |
an object of class |
items |
character, integer, or logical for subsetting the items. |
mscale |
logical. Should the measurement scale labels be used
for creating factor levels? If |
df |
logical. Should a data frame of factors be returned?
If |
... |
currently not used. |
The as.list method coerces item response data to a list
(or data frame) of factors with factor levels either taken from
the mscale(x) or as the values 0, 1, ....
The as.data.frame method returns a data frame with a single
column of class "itemresp".
Furthermore, as.matrix, as.integer, as.double
all return a matrix with the item responses coded as values 0, 1, ...
The as.character method simply calls format.itemresp.
is.itemresp can be used to check wether a given object is of
class "itemresp".
## item responses from binary matrix
x <- cbind(c(1, 0, 1, 0), c(1, 0, 0, 0), c(0, 1, 1, 1))
xi <- itemresp(x)
## change mscale
mscale(xi) <- c("-", "+")
xi
## coercion to list of factors with levels taken from mscale
as.list(xi)
## same but levels taken as integers 0, 1
as.list(xi, mscale = FALSE)
## only for first two items
as.list(xi, items = 1:2)
## result as data.frame
as.list(xi, df = TRUE)
## data frame with single itemresp column
as.data.frame(xi)
## integer matrix
as.matrix(xi)
## character vector
as.character(xi)
## check class of xi
is.itemresp(xi)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.