# R Line Graph

Line Graph represents relation between two variables.

#### Plot a line graph in R

We shall learn to plot a line graph in R programming language with the help of plot() function.

Syntax of plot() function

`plot(x, y, ...)`

where

• x is any R object with a plot method. Ex : numeric vector
• y is any R object with a plot method. Ex : numeric vector
• … is the extra arguments that could be provided, which may contain any of the following
• type  – type could be any of the below values
• ‘p’ – points
• ‘l’ – lines
• ‘b’ – both points and lines
• ‘c’ – for the lines part alone of both points and lines
• ‘o’ – for both points and lines overplotted
• ‘h’ – generates kind of histogram view
• ‘s’ – for stair step look
• ‘S’ – other steps
• ‘n’ – no plotting
• main is the main title for the plot
• sub is the sub title for the plot
• xlab is the x label i.e., title for x-axis
• ylab is the y label i.e., title for y-axis
• asp is the aspect ratio whose value should be given by y/x
• lwd is the line width
• pch is the point character. There are 25 symbols to choose from including alphabetic characters
• col gives the color to points and line

Example 1 : Line Graph

```Line Graph
# R program to plot line graph
x = c(1,2,3,4,5,6,7,8,9,10,11)
y = c(22,13,5,9,25,22,26,1,9,10,2)

# plot function
# except x,y ; rest are optional
plot(x, y, type='b', main='First Plot Example', sub='Line Graph', xlab='time', ylab='cost', asp=1)```

When the above program is run, plot would be generated as a pdf file, by default.

##### Example 2 : Line, No points, Colored line
```Plot Colored Line Graph
# R program to plot line graph
x = c(1,2,3,4,5,6,7,8,9,10,11)
y = c(22,13,5,9,25,22,26,1,9,10,2)

# plot function
# except x,y ; rest are optional
plot(x, y, type='l', col='#ff0000')```

Output  Line Graph Plot

Example 3 : Points, No Line, Colored points

```Plot Colored Line Graph
# R program to plot line graph
x = c(1,2,3,4,5,6,7,8,9,10,11)
y = c(22,13,5,9,25,22,26,1,9,10,2)

# plot function
# except x,y ; rest are optional
plot(x, y, type='p', col='#0000ff')```

Output  Point Graph Plot

Example 4 : Stair Step Graph

```Plot Colored Line Graph
# R program to plot stair graph
x = c(1,2,3,4,5,6,7,8,9,10,11)
y = c(22,13,5,9,25,22,26,1,9,10,2)

# plot function
plot(x, y, type='s', col='#0000ff')```

Output  Stair Graph Plot