Measure of central tendency in R Language represents the whole set of data by single value. It gives us the location of central points. There are three main measures of central tendency:
- Mean
- Median
- Mode
Prerequisite:
Before doing any computation, first of all, we need to prepare our data, save our data in an external .txt or .csv files and it’s a best practice to save the file in the current directory. After that import, your data into R as follow:
Get the csv file here.
# R program to import data into R # Import the data using read.csv() myData = read.csv("CardioGoodFitness.csv", stringsAsFactors = F) # Print the first 6 rows print(head(myData)) |
Output:
Product Age Gender Education MaritalStatus Usage Fitness Income Miles 1 TM195 18 Male 14 Single 3 4 29562 112 2 TM195 19 Male 15 Single 2 3 31836 75 3 TM195 19 Female 14 Partnered 4 3 30699 66 4 TM195 19 Male 12 Single 3 3 32973 85 5 TM195 20 Male 13 Partnered 4 2 35247 47 6 TM195 20 Female 14 Partnered 3 3 32973 66
Functions for computing mean, median and mode:
| Analysis | R Function |
|---|---|
| Mean | mean() |
| Median | median() |
| Mode | mfv() [modeest] |
Mean
It is the sum of observation divided by the total number of observations. It is also defined as average which is the sum divided by count.
where, n = number of terms
Example:
# R program to illustrate # Descriptive Analysis # Import the data using read.csv() myData = read.csv("CardioGoodFitness.csv", stringsAsFactors = F) # Compute the mean value mean = mean(myData$Age) print(mean) |
Output:
[1] 28.78889
Median
It is the middle value of the data set. It splits the data into two halves. If the number of elements in the data set is odd then the center element is median and if it is even then the median would be the average of two central elements.
where, n = number of terms
Example:
# R program to illustrate # Descriptive Analysis # Import the data using read.csv() myData = read.csv("CardioGoodFitness.csv", stringsAsFactors = F) # Compute the median value median = median(myData$Age) print(median) |
Output:
[1] 26
Mode
It is the value that has the highest frequency in the given data set. The data set may have no mode if the frequency of all data points is the same. Also, we can have more than one mode if we encounter two or more data points having the same frequency.
Example:
# R program to illustrate # Descriptive Analysis # Import the library library(modeest) # Import the data using read.csv() myData = read.csv("CardioGoodFitness.csv", stringsAsFactors = F) # Compute the mode value mode = mfv(myData$Age) print(mode) |
Output:
[1] 25
