Function to test for normality of numeric variables in a dataframe

is_normal.R

## Function to test for normality of numeric variables in a dataframe
is.normal <- function(x) {
    z <- lapply(x[sapply(x, is.numeric)], shapiro.test)
    lz <- length(z)
    y <- logical(length = lz)
    for (i in 1:lz) {
        if (z[[i]]$p.value >= 0.1) {
            y[i] <- TRUE
        } else {
            y[i] <- FALSE
        }
    }
        return(y)
    
}