# Draw a Quantile-Quantile Plot in R Programming – qqline() Function

The **Quantile-Quantile Plot in Programming Language**, or (Q-Q Plot) is defined as a value of two variables that are plotted corresponding to each other and check whether the distributions of two variables are similar or not with respect to the locations.** qqline() function in ****R Language** is used to draw a Q-Q Line Plot.

## R – Quantile-Quantile Plot

Syntax:qqline(x, y, col)

Parameters:

x, y:X and Y coordinates of plotcol:It defines color

Returns:A QQ Line plot of the coordinates provided

## Quantile-Quantile Plot in R Example

**Example 1:** Implementation of Basic QQplot Interpretation using qqline() Function in R

## R

`# Set seed for reproducibility` `set.seed` `(500)` `# Create random normally distributed values` `x <- ` `rnorm` `(1200)` `# QQplot of normally distributed values` `qqnorm` `(x)` `# Add qqline to plot` `qqline` `(x, col = ` `"darkgreen"` `)` |

**Output:**

Above is a representation of QQplot of Normally Distributed Random Numbers.

**Example 2:** Implementation of QQplot of Logistically Distributed Values

## R

`# Set seed for reproducibility` `# Random values according to logistic distribution` `# QQplot of logistic distribution` `y <- ` `rlogis` `(800)` `# QQplot of normally distributed values` `qqnorm` `(y)` `# Add qqline to plot` `qqline` `(y, col = ` `"darkgreen"` `)` |

**Output:**

Above is the Q-Q Plot of theoretical quantiles.