One error you may encounter when using R is:
Error in plot.xy(xy.coords(x, y), type = type, ...) :
plot.new has not been called yet
This error occurs when you attempt to perform some action that requires a plot to already exist in R, yet a plot does not exist.
The following examples show how to fix this error in practice.
Example 1: How to Fix Error with lines()
Suppose we attempt to plot a fitted regression line in R:
#create data
df <- data.frame(x=c(1, 2, 2, 3, 5, 6, 8, 8, 9, 9, 10, 11, 12, 15, 15),
y=c(2, 3, 3, 4, 5, 5, 6, 7, 8, 8, 9, 10, 16, 19, 28))
#fit polynomial regression model
model <- lm(y~poly(x, 2), data=df)
#define new sequence of x-values
new_x <- seq(min(df$x), max(df$y))
#attempt to plot fitted regression line
lines(new_x, predict(model, newdata = data.frame(x=new_x)))
Error in plot.xy(xy.coords(x, y), type = type, ...) :
plot.new has not been called yet
We receive an error because we can’t use the lines() function without first creating a plot in R.
To fix this error, we can first create a scatterplot and then use the lines() function:
#create data
df <- data.frame(x=c(1, 2, 2, 3, 5, 6, 8, 8, 9, 9, 10, 11, 12, 15, 15),
y=c(2, 3, 3, 4, 5, 5, 6, 7, 8, 8, 9, 10, 16, 19, 28))
#fit polynomial regression model
model <- lm(y~poly(x, 2), data=df)
#define new sequence of x-values
new_x <- seq(min(df$x), max(df$y))
#create scatterplot of x vs. y values
plot(y~x, data=df)
#attempt to plot fitted regression line
lines(new_x, predict(model, newdata = data.frame(x=new_x)))
Notice that we don’t receive an error because we first used the plot() function before using the lines() function.
Example 2: How to Fix Error with abline()
Suppose we attempt to create a scatterplot with a straight horizontal line in R:
#create data
df <- data.frame(x=c(1, 2, 2, 3, 5, 6, 8, 8, 9, 9, 10, 11, 12, 15, 15),
y=c(2, 3, 3, 4, 5, 5, 6, 7, 8, 8, 9, 10, 16, 19, 28))
#attempt to add horizontal line at y=10
abline(a=10, b=0, lwd=2)
Error in plot.xy(xy.coords(x, y), type = type, ...) :
plot.new has not been called yet
We receive an error because we can’t use the abline() function without first creating a plot in R.
To fix this error, we can first create a scatterplot and then use the abline() function:
#create data
df <- data.frame(x=c(1, 2, 2, 3, 5, 6, 8, 8, 9, 9, 10, 11, 12, 15, 15),
y=c(2, 3, 3, 4, 5, 5, 6, 7, 8, 8, 9, 10, 16, 19, 28))
#create scatterplot of x vs. y
plot(y~x, data=df)
#add horizontal line at y=10
abline(a=10, b=0, lwd=2)
Notice that we don’t receive an error because we first used the plot() function before using the abline() function.
Related: How to Use abline() in R to Add Straight Lines to Plots
Additional Resources
The following tutorials explain how to fix other common errors in R:
How to Fix in R: Unexpected String Constant
How to Fix in R: invalid model formula in ExtractVars
How to Fix in R: argument is not numeric or logical: returning na