The “abline” Function in R

• Package: Base R (no specific package required)

• Purpose: Adds straight lines to a plot.

• General Class: Data Visualization

• Required Argument(s):

• a: Intercept of the line.

• b: Slope of the line.

• Notable Optional Arguments:

• h: Numeric vector of y-values for horizontal lines.

• v: Numeric vector of x-values for vertical lines.

• reg: A linear model fit (object of class “lm”).

• coef: Numeric vector of coefficients for the line.

• col: Color of the line.

• lty: Line type.

• lwd: Line width.

• Example:

• # Example scatter plot
  x <- c(1, 2, 3, 4, 5)
  y <- c(2, 4, 6, 8, 10)
  plot(x, y, main = "Scatter Plot Example", xlab = "X-axis", ylab = "Y-axis", pch = 16)
  
  # Add an abline with intercept 1 and slope 2
  abline(a = 1, b = 2, col = "red", lty = 2, lwd = 2)

• In this example, the abline function is used to add a line to a scatter plot with an intercept of 1 and a slope of 2. Additional arguments specify the color, line type, and line width. The resulting plot includes the scatter plot and the added line.