How to Use text() Function in R to Add Text to Plot


You can use the text() function to add text to a plot in base R.

This function uses the following basic syntax:

text(x, y, “my text”)

where:

  • x, y: The (x, y) coordinates where the text should be placed.

The following examples show how to use this function in practice.

Example 1: Add One Text Element to Plot

The following code shows how to use text() to add one text element to a plot at (x, y) coordinates of (5, 18):

#create data frame with values to plot
df <- data.frame(x=c(1, 4, 7, 8, 8, 10),
                 y=c(4, 9, 16, 14, 12, 20))

#create scatterplot
plot(df$x, df$y)

#add text element at (5, 18)
text(x=5, y=18, "this is my text")

Notice that our text element has been added to the (x, y) coordinates of (5, 18) in the plot.

Example 2: Add Multiple Text Elements to Plot

To add multiple text elements to a plot, we can simply use multiple text() functions:

#create data frame with values to plot
df <- data.frame(x=c(1, 4, 7, 8, 8, 10),
                 y=c(4, 9, 16, 14, 12, 20))

#create scatterplot
plot(df$x, df$y)

#add text elements
text(x=5, y=18, "first text")
text(x=5, y=10, "second text") 
text(x=5, y=5, "third text") 

R add multiple text elements to plot

Notice that three text elements have been added to the plot, each at the (x, y) coordinates that we specified.

Example 3: Customize Text Elements in Plot

We can use the cex, col, and font arguments to customize the size, color, and font style of the text elements in the plot, respectively:

#create data frame with values to plot
df <- data.frame(x=c(1, 4, 7, 8, 8, 10),
                 y=c(4, 9, 16, 14, 12, 20))

#create scatterplot
plot(df$x, df$y)

#add text elements with custom appearance
text(x=5, y=18, "first text", col='red')
text(x=5, y=10, "second text", col='blue', cex=3) 
text(x=5, y=5, "third text", col='green', cex=5, font=3) 

custom text in R plot

Notice that each of the three text elements have a custom appearance.

Also note that the font argument takes four possible values:

  • 1: plain
  • 2: bold
  • 3: italic
  • 4: bold-italic

Since we specified font=3 for our third text element, the font is italic.

Example 4: Add Text Labels to Each Point in Plot

We can use the labels arguments to add a text label to each point in the plot:

#create data frame with values to plot
df <- data.frame(teams=c('A', 'B', 'C', 'D', 'E', 'F'),
                 x=c(1, 4, 7, 8, 8, 10),
                 y=c(4, 9, 16, 14, 12, 20))

#create scatterplot
plot(df$x, df$y)

#add text label to each point in plot
text(df$x, df$y, labels=df$teams, pos=4)

r add text labels to plot

Notice that each of the points in the plot now have a text label.

Also note that the pos argument controls where the text label is placed relative to the point and takes four possible values:

  • 1: below text
  • 2: left of text
  • 3: above text
  • 4: right of text

Since we specified pos=4 each text label is placed to the right of the points in the plot.

Additional Resources

The following tutorials explain how to use other common functions in R:

How to Use paste & paste0 Functions in R
How to Use the replace() Function in R
How to Use the View() Function in R

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