This function gives the equivalent latent classes which have the same category success probabilities for each category or item.

LC2LG(Q, sequential = FALSE, att.str = NULL)

Arguments

Q

A required \(J \times K\) binary Q-matrix. J represents test length and K represents the number of attributes of this test. Entry 1 at row j and column k represents the \(k^{th}\) attribute is measured by item \(j\), and 0 means item \(j\) does not measure attribute \(k\).

sequential

logical; whether the Q-matrix is a Qc-matrix for sequential models?

att.str

attribute structure. See GDINA for details.

Value

An item or category by latent class matrix. In the G-DINA model, if item j measures \(Kj\) attributes, \(2^K\) latent classes can be combined into \(2^{Kj}\) latent groups. This matrix gives which latent group each of \(2^K\) latent classes belongs to for each item.

Author

Wenchao Ma, The University of Alabama, wenchao.ma@ua.edu
Jimmy de la Torre, The University of Hong Kong

Examples

attributepattern(3)
#>      A1 A2 A3
#> [1,]  0  0  0
#> [2,]  1  0  0
#> [3,]  0  1  0
#> [4,]  0  0  1
#> [5,]  1  1  0
#> [6,]  1  0  1
#> [7,]  0  1  1
#> [8,]  1  1  1

q <- matrix(scan(text = "0 1 0 1 0 1 1 1 0"),ncol = 3)
q
#>      [,1] [,2] [,3]
#> [1,]    0    1    1
#> [2,]    1    0    1
#> [3,]    0    1    0
LC2LG(Q = q)
#>      000 100 010 001 110 101 011 111
#> [1,]   1   1   2   3   2   3   4   4
#> [2,]   1   2   1   3   2   4   3   4
#> [3,]   1   1   2   1   2   1   2   2