R – Line Graphs

A line graph is a chart that is used to display information in the form of a series of data points. It utilizes points and lines to represent change over time. Line graphs are drawn by plotting different points on their X coordinates and Y coordinates, then by joining them together through a line from beginning to end. The graph represents different values as it can move up and down based on the suitable variable.

R – Line Graphs

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

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

Parameters:

• v: This parameter is a contains only the numeric values
• type: This parameter has the following value: 
  1. “p” : This value is used to draw only the points.
  2. “l” : This value is used to draw only the lines.
  3. “o”: This value is used to draw both points and lines
• xlab: This parameter is the label for x axis in the chart.
• ylab: This parameter is the label for y axis in the chart.
• main: This parameter main is the title of the chart.
• col: This parameter is used to give colors to both the points and lines.

Creating a Simple Line Graph

Approach: In order to create a line graph: 

1. It is created using the type parameter as “o” and input vector.
2. Below code to describe the line graph.

Example:

R

# Create the data for the chart.
v <- c(17, 25, 38, 13, 41)

# Plot the bar chart.
plot(v, type = "o")

Output:

Adding Title, Color and Labels in Line Graphs in R

Approach: To create a colored and labeled line chart. 

1. Take all parameters which are required to make line chart by giving a title to the chart and add labels to the axes.
2. We can add more features by adding more parameters with more colors to the points and lines.

Example:

R

# Create the data for the chart.
v <- c(17, 25, 38, 13, 41)

# Plot the bar chart.
plot(v, type = "o", col = "green",
    xlab = "Month", ylab = "Article Written",
    main = "Article Written chart")

Output:

Multiple Lines in a Line Graph in R Programming Language

Approach: To create multiple line graphs. 

1. In above example, we created line graphs by only one line in each graph.
2. Now creating multiple lines to describe it more clearly.

Example:

R

# Create the data for the chart.
v <- c(17, 25, 38, 13, 41)
t <- c(22, 19, 36, 19, 23)
m <- c(25, 14, 16, 34, 29)

# Plot the bar chart.
plot(v, type = "o", col = "red",
    xlab = "Month", ylab = "Article Written ",
    main = "Article Written chart")

lines(t, type = "o", col = "blue")
lines(m, type = "o", col = "green")

Output: When we execute the above code, it shows the following result-