irt (version 0.2.9)

as.data.frame.Item: Convert an Item-class object into a data.frame.

Description

This function converts Item-class objects to a data.frame object.

This function converts Itempool-class objects to a data.frame object.

This function converts Testlet-class objects to a data.frame object. If testlet has an ID, an additional column will be created for the testlet ID.

Usage

# S3 method for Item
as.data.frame(x, row.names = NULL, optional = FALSE, ..., include_se = TRUE)
# S3 method for GRM
as.data.frame(x, row.names = NULL, optional = FALSE, ..., include_se = TRUE)
# S3 method for PCM
as.data.frame(x, row.names = NULL, optional = FALSE, ..., include_se = TRUE)
# S3 method for GPCM
as.data.frame(x, row.names = NULL, optional = FALSE, ..., include_se = TRUE)
# S3 method for GPCM2
as.data.frame(x, row.names = NULL, optional = FALSE, ..., include_se = TRUE)
# S3 method for M2PL
as.data.frame(x, row.names = NULL, optional = FALSE, ..., include_se = TRUE)
# S3 method for M3PL
as.data.frame(x, row.names = NULL, optional = FALSE, ..., include_se = TRUE)
# S3 method for Itempool
as.data.frame(x, row.names = NULL, optional = FALSE, ..., include_se = TRUE)
# S3 method for Testlet
as.data.frame(x, row.names = NULL, optional = FALSE, ..., include_se = TRUE)

Value

A data frame representation of the item.

A data frame representation of the GRM item.

A data frame representation of the PCM item.

A data frame representation of the GPCM item.

A data frame representation of the GPCM2 item.

A data frame representation of the M2PL item.

A data frame representation of the M3PL item.

A data frame of items within each row. If all items cannot be coerced to a data.frame, an list of items will be returned and a warning will be raised.

A data frame representation of the item.

Arguments

x

An Testlet-class object

row.names

NULL or a character vector giving the row name for the data frame. Missing values are not allowed.

optional

logical. If TRUE, setting row names and converting column names

...

additional arguments

include_se

If TRUE, and items have se_parameters, those will be included in the data frame.

Author

Emre Gonulates

Examples

item1 <- generate_item()
as.data.frame(item1)

item2 <- generate_item(model = "Rasch", item_id = "i1",
                       misc = list(type = "MC", op = TRUE, c("i1", "i2")))
as.data.frame(item2)

item3 <- generate_item(model = "GRM")
as.data.frame(item3)

item1 <- generate_item(model = "GRM", item_id = "i1")
as.data.frame(item1)
item1 <- generate_item(model = "PCM", item_id = "i1")
as.data.frame(item1)
item1 <- generate_item(model = "GPCM", item_id = "i1")
as.data.frame(item1)
item1 <- generate_item(model = "GPCM2", item_id = "i1")
as.data.frame(item1)
item1 <- generate_item(model = "M2PL", item_id = "i1")
as.data.frame(item1)
item1 <- generate_item(model = "M3PL", item_id = "i1")
as.data.frame(item1)
ip1 <- generate_ip()
as.data.frame(ip1)

ip2 <- generate_ip(n = 10, model = "GRM",
                   content = sample(c("G", "A"), 10, TRUE),
                   item_id = paste0("grm-i-", 1:10))
as.data.frame(ip2)

t1 <- generate_testlet(n = 3, item_id_preamble = "t1")
t2 <- generate_testlet(n = 2, item_id_preamble = "t2")
ip3 <- c(ip1, t1, t2)
as.data.frame(ip3)

ip4 <- c(ip2, ip3)
as.data.frame(ip4)


item1 <- item(a = 1.12, b = -2.1, c = 0.28)
item2 <- item(a = 2, b = 3.2, c = 0.21)

ip1 <- c(item1, item2)
as.data.frame(ip1)
testlet1 <- generate_testlet()
as.data.frame(testlet1)
testlet2 <- generate_testlet(testlet_id = "T1")
as.data.frame(testlet2)