# R/summary.pwrrasch.R In pwrRasch: Statistical Power Simulation for Testing the Rasch Model

#### Documented in summary.pwrrasch

```#' Object Summary
#'
#' Generic \code{summary} function for the \code{pwrrasch} object
#'
#' @param object      \code{pwrrasch} object
#' @param ...         Additional arguments affecting the summary produced.
#'
#' @author
#' Takuya Yanagida \email{[email protected]@univie.ac.at},
#' Jan Steinfeld \email{[email protected]@univie.ac.at}
#'
#' @export
#'
#' @examples
#' \dontrun{
#'
#' # item parameters
#' ipar2 <- ipar1 <- seq(-3, 3, length.out = 20)
#' # model differential item function (DIF)
#' ipar2[9] <- ipar1[12]
#' ipar2[12] <- ipar1[9]
#' # simulation for b = 100
#' simres <- pwr.rasch(100, ipar = list(ipar1, ipar2))
#' summary(simres)
#'
#' # item parameters
#' ipar2 <- ipar1 <- seq(-3, 3, length.out = 20)
#' # model differential item function (DIF)
#' ipar2[10] <- ipar1[11]
#' ipar2[11] <- ipar1[10]
#' # simulation for b = 100, 200, 300, 400, 500
#' simres <- pwr.rasch(seq(100, 500, by = 100), ipar = list(ipar1, ipar2))
#' summary(simres)
#' }
summary.pwrrasch <- function(object, ...) {

if (length(object[[1]]) == 1) {

if ("type1" %in% names(object)) {

with(object, {

cat("\n Statistical Power Simulation for the Rasch model \n\n",

"   b (number of persons in each group): ", b, "\n",
"   c (number of items):                 ", c, "\n",
"   simulation runs:                     ", runs, "\n\n",

"   Estimated statistical power: ", formatC(sum(H1.AC.p < sig.level) / runs, format = "f", digits = 3), "\n",
"   Nominal significance level:  ", sig.level, "\n",
"   Empirical significance level:", formatC(sum(H0.AC.p < sig.level) / runs, format = "f", digits = 3), "\n\n")

})

} else {

with(object, {

cat("\n Statistical Power Simulation for the Rasch model \n\n",

"   b (numer of persons in each group): ", b, "\n",
"   c (numer of items):                 ", c, "\n",
"   simulation runs:                    ", runs, "\n\n",

"   Estimated statistical power: ", formatC(sum(H1.AC.p < sig.level) / runs, format = "f", digits = 3), "\n",
"   Nominal significance level:  ", sig.level, "\n\n")

})

}

#--------------------------------------------------------------------------------------------------------#
# length(object) > 1

} else {

b <- unlist(lapply(object, function(x) x\$b))
c <- unique(unlist(lapply(object, function(x) x\$c)))
runs <- unique(unlist(lapply(object, function(x) x\$runs)))
pwr <- unlist(lapply(object, function(x) x\$power))
type1 <- unlist(lapply(object, function(x) x\$type1))

###

cat("\n Statistical Power Simulation for the Rasch model \n\n",

"   b (numer of persons in each group): ", paste(b, collapse = ", "), "\n",
"   c (numer of items):                 ", c, "\n",
"   simulation runs:                    ", runs, "\n\n",

"   Estimated statistical power: \n")

for (i in 1:length(object)) {

cat(paste0("      b = ", formatC(object[[i]]\$b, digits = max(nchar(object[[i]]\$b)) - 1, format = "d"), ":"),
formatC(object[[i]]\$power, format = "f", digits = 3) , "\n")

}

###

if (!is.null(type1)) {

cat("\n   Empirical significance level: \n")
for (i in 1:length(object)) {

cat(paste0("      b = ", formatC(object[[i]]\$b, digits = max(nchar(object[[i]]\$b)) - 1, format = "d"), ":"),
formatC(object[[i]]\$type1, format = "f", digits = 3) , "\n")

}

}

cat("\n")

}

}
```

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pwrRasch documentation built on May 29, 2017, 2:11 p.m.