This function computes Tau-Congeneric Measurement, also known as McDonald's tau coefficient, for a given data set.
OmegaCoefficient(x, na = NULL, Z = NULL, w = NULL)
For a correlation/covariance matrix input, returns a single numeric value representing the omega coefficient. For a data matrix input, returns a list with three components:
OmegaCov: Omega coefficient calculated from covariance matrix
OmegaPhi: Omega coefficient calculated from phi coefficient matrix
OmegaTetrachoric: Omega coefficient calculated from tetrachoric correlation matrix
This should be a data matrix or a Covariance/Phi/Tetrachoric matrix.
This parameter identifies the numbers or characters that should be treated as missing values when 'x' is a data matrix.
This parameter represents a missing indicator matrix. It is only needed if 'x' is a data matrix.
This parameter is an item weight vector. It is only required if 'x' is a data matrix.
McDonald, R. P. (1999). Test theory: A unified treatment. Erlbaum.