- R Tutorial
- R - Home
- R - Overview
- R - Environment Setup
- R - Basic Syntax
- R - Data Types
- R - Variables
- R - Operators
- R - Decision Making
- R - Loops
- R - Functions
- R - Strings
- R - Vectors
- R - Lists
- R - Matrices
- R - Arrays
- R - Factors
- R - Data Frames
- R - Packages
- R - Data Reshaping

- R Data Interfaces
- R - CSV Files
- R - Excel Files
- R - Binary Files
- R - XML Files
- R - JSON Files
- R - Web Data
- R - Database

- R Charts & Graphs
- R - Pie Charts
- R - Bar Charts
- R - Boxplots
- R - Histograms
- R - Line Graphs
- R - Scatterplots

- R Statistics Examples
- R - Mean, Median & Mode
- R - Linear Regression
- R - Multiple Regression
- R - Logistic Regression
- R - Normal Distribution
- R - Binomial Distribution
- R - Poisson Regression
- R - Analysis of Covariance
- R - Time Series Analysis
- R - Nonlinear Least Square
- R - Decision Tree
- R - Random Forest
- R - Survival Analysis
- R - Chi Square Tests

- R Useful Resources
- R - Interview Questions
- R - Quick Guide
- R - Useful Resources
- R - Discussion

- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who

# R - Line Graphs

A line chart is a graph that connects a series of points by drawing line segments between them. These points are ordered in one of their coordinate (usually the x-coordinate) value. Line charts are usually used in identifying the trends in data.

The **plot()** function in R is used to create the line graph.

### Syntax

The basic syntax to create a line chart in R is −

plot(v,type,col,xlab,ylab)

Following is the description of the parameters used −

**v**is a vector containing the numeric values.**type**takes the value "p" to draw only the points, "l" to draw only the lines and "o" to draw both points and lines.**xlab**is the label for x axis.**ylab**is the label for y axis.**main**is the Title of the chart.**col**is used to give colors to both the points and lines.

### Example

A simple line chart is created using the input vector and the type parameter as "O". The below script will create and save a line chart in the current R working directory.

# Create the data for the chart. v <- c(7,12,28,3,41) # Give the chart file a name. png(file = "line_chart.jpg") # Plot the bar chart. plot(v,type = "o") # Save the file. dev.off()

When we execute the above code, it produces the following result −

## Line Chart Title, Color and Labels

The features of the line chart can be expanded by using additional parameters. We add color to the points and lines, give a title to the chart and add labels to the axes.

### Example

# Create the data for the chart. v <- c(7,12,28,3,41) # Give the chart file a name. png(file = "line_chart_label_colored.jpg") # Plot the bar chart. plot(v,type = "o", col = "red", xlab = "Month", ylab = "Rain fall", main = "Rain fall chart") # Save the file. dev.off()

When we execute the above code, it produces the following result −

## Multiple Lines in a Line Chart

More than one line can be drawn on the same chart by using the **lines()**function.

After the first line is plotted, the lines() function can use an additional vector as input to draw the second line in the chart,

# Create the data for the chart. v <- c(7,12,28,3,41) t <- c(14,7,6,19,3) # Give the chart file a name. png(file = "line_chart_2_lines.jpg") # Plot the bar chart. plot(v,type = "o",col = "red", xlab = "Month", ylab = "Rain fall", main = "Rain fall chart") lines(t, type = "o", col = "blue") # Save the file. dev.off()

When we execute the above code, it produces the following result −