The “qqplot” Function in R

• Package: Base R (stats package)

• Purpose: To create a quantile-quantile (Q-Q) plot for visualizing the distribution of a dataset against a theoretical distribution (e.g., normal distribution).

• General Class: Statistical Visualization

• Required Argument(s):

• x: A numeric vector or a data frame.

• y: A second numeric vector or a data frame for comparison.

• Notable Optional Arguments:

• plot.it: A logical value indicating whether to create the Q-Q plot (default is TRUE).

• ...: Additional arguments passed to or from other methods.

• Example:

• # Example usage
  # Generate two random samples from normal distributions
  data_x <- rnorm(100) # Distribution being tested
  data_y <- rnorm(100) # Reference distribution
  
  # Create a Q-Q plot comparing the two samples
  qqplot(data_x, data_y)

• In this example, both x and y are provided, and the qqplot function from the stats package is used to create a Q-Q plot for comparing two random samples from normal distributions.