xxirt_createThetaDistribution.Rd
Creates a user defined theta distribution.
xxirt_createThetaDistribution(par, est, P, prior=NULL, prior_par1=NULL, prior_par2=NULL)
par | Parameter vector with starting values |
---|---|
est | Vector of logicals indicating which parameters should be estimated |
P | Distribution function for \(\bold{\theta}\) |
prior | Prior distribution |
prior_par1 | First parameter of prior distribution |
prior_par2 | Second parameter of prior distribution |
############################################################################# ## EXAMPLE 1: Definition of theta distribution ############################################################################# #** theta grid Theta <- matrix( seq(-10,10,length=31), ncol=1 ) #** theta distribution P_Theta1 <- function( par, Theta, G){ mu <- par[1] sigma <- max( par[2], .01 ) TP <- nrow(Theta) pi_Theta <- matrix( 0, nrow=TP, ncol=G) pi1 <- stats::dnorm( Theta[,1], mean=mu, sd=sigma ) pi1 <- pi1 / sum(pi1) pi_Theta[,1] <- pi1 return(pi_Theta) } #** create distribution class par_Theta <- c( "mu"=0, "sigma"=1 ) customTheta <- sirt::xxirt_createThetaDistribution( par=par_Theta, est=c(FALSE,TRUE), P=P_Theta1 )