cor.poly: Polychoric Correlation Matrix

In misty: Miscellaneous Functions 'T. Yanagida'

Polychoric Correlation Matrix

Description

This function computes a polychoric correlation matrix, which is the estimated Pearson product-moment correlation matrix between underlying normally distributed latent variables which generate the ordinal scores.

Usage

cor.poly(x, smooth = TRUE, global = TRUE, weight = NULL, correct = 0,
         progress = TRUE, na.rm = TRUE, delete = TRUE,
         tri = c("both", "lower", "upper"), digits = 2, as.na = NULL,
         check = TRUE, output = TRUE)

Arguments

x	a matrix or data frame of discrete values.
smooth	logical: if TRUE and if the polychoric matrix is not positive definite, a simple smoothing algorithm using cor.smooth() function is applied.
global	logical: if TRUE, the global values of the tau parameter is used instead of the local values.
weight	a vector of length of the number of observations that specifies the weights to apply to each case. The NULL case is equivalent of weights of 1 for all cases.
correct	a numeric value indicating the correction value to use to correct for continuity in the case of zero entry. Note that unlike in the polychoric() function in the psych the default value is 0.
progress	logical: if TRUE, the progress bar is shown.
na.rm	logical: if TRUE, missing data are deleted.
delete	logical: if TRUE, cases with no variance are deleted with a warning before proceeding.
tri	a character string indicating which triangular of the matrix to show on the console, i.e., both for upper and lower triangular, lower (default) for the lower triangular, and upper for the upper triangular.
digits	an integer value indicating the number of decimal places to be used for displaying correlation coefficients.
as.na	a numeric vector indicating user-defined missing values, i.e. these values are converted to NA before conducting the analysis.
check	logical: if TRUE, argument specification is checked.
output	logical: if TRUE, output is shown on the console.

Value

Returns an object of class misty.object, which is a list with following entries:

call	function call
type	type of analysis
data	matrix or data frame specified in x
args	specification of function arguments
result	result table

Note

This function is based on the polychoric() function in the psych package by William Revelle.

Author(s)

William Revelle

References

Revelle, W. (2018) psych: Procedures for personality and psychological research. Northwestern University, Evanston, Illinois, USA, https://CRAN.R-project.org/package=psych Version = 1.8.12.

Examples

dat <- data.frame(x1 = c(1, 1, 3, 2, 1, 2, 3, 2, 3, 1),
                  x2 = c(1, 2, 1, 1, 2, 2, 2, 1, 3, 1),
                  x3 = c(1, 3, 2, 3, 3, 1, 3, 2, 1, 2))

# Polychoric correlation matrix
cor.poly(dat)

misty documentation built on Nov. 15, 2023, 1:06 a.m.