ccov.np function.
detect.index(ccovtable, itemcluster)ccov.np.
data (submitted to ccov.np).
Zhang, J., & Stout, W. (1999a). Conditional covariance structure of generalized compensatory multidimensional items. Psychometrika, 64, 129-152.
Zhang, J., & Stout, W. (1999b). The theoretical DETECT index of dimensionality and its application to approximate simple structure. Psychometrika, 64, 213-249.
Zhang, J. (2007). Conditional covariance theory and DETECT for polytomous items. Psychometrika, 72, 69-91.
conf.detect.