R/Psych24.R

In mhahsler/seriation: Infrastructure for Ordering Objects Using Seriation

#' Results of 24 Psychological Test for 8th Grade Students
#'
#' A data set collected by Holzinger and Swineford (1939) which consists of the
#' results of 24 psychological tests given to 145 seventh and eighth grade
#' students in a Chicago suburb. This data set contains the correlation matrix
#' for the 24 test results.
#' The data set was also used as an example for visualization of cluster analysis
#' by Ling (1973).
#'
#' @name Psych24
#' @aliases Psych24
#' @docType data

#' @format
#'  A 24 x 24 correlation matrix.
#' @references
#' Holzinger, K. L., Swineford, F. (1939):
#' A study in factor analysis: The stability of a bi-factor solution.
#' _Supplementary Educational Monograph,_ No. **48**.
#' Chicago: University of Chicago Press.
#'
#' Ling, R. L. (1973): A computer generated aid for cluster analysis.
#' _Communications of the ACM,_
#' **16**(6), pp. 355--361.
#' @examples
#' data("Psych24")
#'
#' ## create a dist object and also get rid of the one negative entry in the
#' ## correlation matrix
#' d <- as.dist(1 - abs(Psych24))
#'
#' pimage(d)
#'
#' ## do hclust as in Ling (1973)
#' hc <- hclust(d, method = "complete")
#' plot(hc)
#'
#' pimage(d, hc)
#'
#' ## use seriation
#' order <- seriate(d, method = "tsp")
#' #order <- seriate(d, method = "tsp", control = list(method = "concorde"))
#' pimage(d, order)
#' @keywords datasets
NULL