R/tam_dtnorm.R

In TAM: Test Analysis Modules

## File Name: tam_dtnorm.R
## File Version: 0.11

#--- This is a copy of msm::dtnorm
tam_dtnorm <- function(x, mean=0, sd=1, lower=-Inf, upper=Inf, log=FALSE)
{
    ret <- numeric(length(x))
    ret[x < lower | x > upper] <- if (log) { -Inf } else { 0 }
    ret[upper < lower] <- NaN
    ind <- x >=lower & x <=upper
    if (any(ind)) {
        denom <- stats::pnorm(q=upper, mean=mean, sd=sd) - stats::pnorm(q=lower, mean=mean, sd=sd)
        xtmp <- stats::dnorm(x=x, mean=mean, sd=sd, log=log)
        if (log)
            xtmp <- xtmp - log(denom)
        else xtmp <- xtmp/denom
        ret[x >=lower & x <=upper] <- xtmp[ind]
    }
    return(ret)
}