R Error in hist.default : ‘x’ must be numeric (2 Examples)
In this tutorial, I’ll illustrate how to handle the error in hist.default(X) : ‘x’ must be numeric in R.
The tutorial will contain two examples for the error message “x must be numeric”. To be more specific, the article will contain these content blocks:
Let’s take a look at some R codes in action…
Creation of Example Data
We’ll use the following data as basement for this R tutorial:
set.seed(64982057) # Create example data my_data <- as.character(round(rnorm(200), 2)) my_data # Print first values of data #  "-0.1" "0.65" "-0.71" "-0.55" "-1.93" "1.69" "-0.91" "-1.02" "0.28" "0.3" ...
The previous output of the RStudio console shows the structure of our exemplifying data – It’s a vector of random numbers.
Let’s assume that we want to draw these random numbers in a histogram…
Example 1: Reproduce the Error in hist.default(X) : ‘x’ must be numeric
In this example, I’ll illustrate how to replicate the error message in hist.default(X) : ‘x’ must be numeric.
Consider that we want to apply the hist function to our random data:
hist(my_data) # Trying to create histogram # Error in hist.default(my_data) : 'x' must be numeric
As you can see, the previous R code returned the error in hist.default(my_data) : ‘x’ must be numeric.
The reason for this is that our input data is not numeric. We can check that by using the class function:
class(my_data) # Checking class of data #  "character"
Let’s solve this problem…
Example 2: Fix the Error in hist.default(X) : ‘x’ must be numeric
Example 2 shows how to get rid of the error in hist.default(X) : ‘x’ must be numeric. For this, we have to convert our data from character to numeric:
my_data_num <- as.numeric(my_data) # Convert character to numeric my_data_num # Print first values of data #  -0.10 0.65 -0.71 -0.55 -1.93 1.69 -0.91 -1.02 0.28 0.30 ...
Now, we can apply the hist function to our updated data:
hist(my_data_num) # Draw histogram in R
Figure 1 shows the output of the previous R programming syntax: A histogram created by the hist function of Base R.
Video, Further Resources & Summary
Have a look at the following video of my YouTube channel. In the video, I’m illustrating the contents of this article.
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Furthermore, you might read the related tutorials on my website.
In this R post you learned how to deal with the error in hist.default(X) : ‘x’ must be numeric. Please note that this error message can also occur when using other functions that need numeric values as input such as the cor() function when calculating correlations.
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