หลีกเลี่ยงการใช้ .

# Define a function to prevent pasting the code above
ci <- function(x, plot.it = FALSE) {
  # Plot the data
  if (isTRUE(plot.it)) hist(x)
  
  m <- mean(x); s <- sd(x); n <- length(x)
  c(m - 1.96 * s/sqrt(n), m + 1.96 * s/sqrt(n))
}

# Generate 100 normal random numbers
sample.values <- rnorm(100)
ci(sample.values)