How to perform univariate analysis in R with examples?

Univariate analysis is a statistical method used to analyze one variable at a time in order to gain insights and understand its characteristics. In R, this type of analysis can be performed using various techniques and functions available in the software.

To perform univariate analysis in R, the first step is to import the data set into the R environment. This can be done using the “read.csv” function or by manually entering the data into a data frame.

Once the data is imported, basic summary statistics such as mean, median, and standard deviation can be calculated using the “summary” function. This provides a quick overview of the data and helps identify any outliers or unusual values.

Next, graphical representations such as histograms, box plots, and scatter plots can be created using the “ggplot2” package. These plots help visualize the distribution and patterns in the data.

Further analysis can be performed by using functions such as “t.test” for hypothesis testing or “cor.test” for correlation analysis. These functions provide statistical significance and quantify the relationship between variables.

To better understand the process, let’s consider an example of univariate analysis in R. Suppose we have a data set of student grades and want to analyze the scores for a particular subject. After importing the data, we can use the “summary” function to get the mean, median, and other summary statistics of the scores. We can then create a histogram to visualize the distribution of scores and use the “t.test” function to compare the mean scores of two groups, such as male and female students.

In conclusion, univariate analysis in R allows for a thorough understanding of a single variable and its relationship with other variables. With the various tools and functions available, it is a powerful method for analyzing data and drawing meaningful conclusions.

Perform Univariate Analysis in R (With Examples)


The term  refers to the analysis of one variable. You can remember this because the prefix “uni” means “one.”

There are three common ways to perform univariate analysis on one variable:

1. Summary statistics – Measures the center and spread of values.

2. Frequency table – Describes how often different values occur.

3. Charts – Used to visualize the distribution of values.

This tutorial provides an example of how to perform univariate analysis for the following variable:

#create variable with 15 values
x <- c(1, 1, 2, 3.5, 4, 4, 4, 5, 5, 6.5, 7, 7.4, 8, 13, 14.2)

Summary Statistics

We can use the following syntax to calculate various summary statistics for our variable:

#find mean
mean(x)
[1] 5.706667

#find median
median(x)

[1] 5

#find range
max(x) - min(x)

[1] 13.2

#find interquartile range (spread of middle 50% of values)
IQR(x)

[1] 3.45

#find standard deviation
sd(x)

[1] 3.858287

Frequency Table

We can use the following syntax to produce a frequency table for our variable:

#produce frequency table
table(x)

   1    2  3.5    4    5  6.5    7  7.4    8   13  14.2 
   2    1    1    3    2    1    1    1    1    1     1 

This tells us that:

  • The value 1 occurs 2 times
  • The value 2 occurs 1 time
  • The value 3.5 occurs 1 time

And so on.

Charts

#produce boxplot
boxplot(x)

We can produce a histogram using the following syntax: 

#produce histogram
hist(x)

We can produce a using the following syntax: 

#produce density curve
plot(density(x))

Each of these charts give us a unique way to visualize the distribution of values for our variable.


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