How to find the statistical mode in R?

The “mode” of a dataset is the most frequently occurring value(s). Unlike mean or median, R doesn’t offer a built-in function for the mode, so you often create a custom function or use a specialized package.

Custom Base R Function
Here’s a quick way to get all modes (in case of ties) using base R:

mode_func <- function(x) {
  freq_table <- table(x)
  max_freq <- max(freq_table)
  names(freq_table)[freq_table == max_freq]
}

# Example usage
v <- c(2, 3, 3, 5, 2, 3, 7)
mode_func(v)
# Returns "3" because 3 appears most frequently

table(x) counts how often each unique value appears.
max(freq_table) finds the highest frequency.
names(freq_table)[freq_table == max_freq] returns the value(s) that have that highest frequency.

Using a Package (Optional)
Some packages, like DescTools, include a built-in Mode() function:

install.packages("DescTools")
library(DescTools)

Mode(v)

This can be more convenient if you prefer not to define a custom function.

Note on Data Types

For numeric vectors, the above approach works fine.
For character or factor vectors, you can use the same logic; just be aware that table() treats them as categories.

Further Learning
If you’re enhancing your R and problem-solving skills for coding interviews, these courses can help:

If you’re also interested in designing scalable systems, check out Grokking System Design Fundamentals. For personalized guidance, consider a Coding Mock Interview with ex-FAANG engineers. You can also explore the DesignGurus.io YouTube channel for concise tutorials and insights.

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