get_ss {scaleAlign}

Get sufficient statistics

Description

Find sufficient statistics from a data set

Usage

get_ss(dat)

Arguments

dat

Data set with items as columns and examinees as rows. Missing responses should be coded as NA.

Value

Vector of sufficient statistics

Examples

set.seed(2524)

diff_1 <- rnorm(10)
diff_2 <- rnorm(10)

N <- 500

th <- MASS::mvrnorm(N, mu = c(0, -1),
                    Sigma = matrix(c(1, .5 * 2, .5 * 2, 4), nrow = 2))

probs_1 <- 1 / (1 + exp(-outer(th[, 1], diff_1, "-")))
probs_2 <- 1 / (1 + exp(-outer(th[, 2], diff_2, "-")))

probs <- cbind(probs_1, probs_2)

dat <- apply(probs, 2, function(p) as.numeric(p > runif(N)))

get_ss(dat)