Last active
May 28, 2016 21:41
-
-
Save pdparker/53502f6ffc61dd2d155388d488e0b136 to your computer and use it in GitHub Desktop.
Get loadings and residuals to give a particular Omega reliability
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
findValues <- function(reliability, n=6, n.total=100){ | |
require(MASS) | |
f = function(L,reliability, n){-reliability+(L*n)^2/((L*n)^2 + (1- L^2)*n)} | |
#Base loadings residuals on that | |
L <- uniroot(f,interval = c(0,1), reliability=reliability, n = n)$root | |
R <- 1-L^2 | |
out<- sprintf("The sum of the loadings must equal: %f and the residual: %f\n | |
For a Tau equaivilent model - \nEach loading should be: %f and each residual: %f", | |
L*n, R*n, L, R) | |
lamba <- matrix(rep(L,n)) | |
tau <- diag(rep(R,n)) | |
m <- lamba %*% t(lamba) + tau | |
data <- mvrnorm(n = n.total,rep(0,n), m,empirical = TRUE) | |
cat(out) | |
return(invisible(list(data=data, loading = L, residual = R, implied.covar = m, n.items = n, n.sample = n.total))) | |
} | |
test <- findValues(reliability = .95, n.total = 1000) | |
psych::omega(test$data) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment