Check if Column Exists in Data Frame in R (Example)
In this R tutorial you’ll learn how to inspect whether a variable exists in a data frame.
Table of contents:
Sound good? Let’s jump right to the examples:
In the example of this R tutorial, we’ll use the following data frame as basement:
data <- data.frame(col1 = 1:5, # Create example data col2 = letters[1:5], col3 = 3) data # Inspect example data # col1 col2 col3 # 1 1 a 3 # 2 2 b 3 # 3 3 c 3 # 4 4 d 3 # 5 5 e 3
Our example data contains five rows and three columns. The variables are called col1, col2, and col3.
Example: Search for Column Name in Data Frame
If we want to find a variable in a data frame, we can use a combination of the %in%-operator and the colnames function:
"col3" %in% colnames(data) # Check if column exists # TRUE
As you can see, the previous R code returned the logical value TRUE to the RStudio console. This means that the column name “col3” exists in our data frame.
Let’s check another column name:
"other_col" %in% colnames(data) # Column does not exist # FALSE
The RStudio console returns FALSE, i.e. the variable “other_col” is not existing in our data matrix.
Video, Further Resources & Summary
I have recently published a video on the Statistics Globe YouTube channel, which explains the content of this tutorial. You can find the video below.
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Furthermore, you might want to have a look at some of the other tutorials of my website. You can find a selection of other tutorials below.
Summary: At this point you should have learned how to look for certain column names in a data matrix in the R programming language. If you have any additional comments and/or questions, let me know in the comments section.
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