# Get Standard Deviation of a Column in R dataframe

Last Updated : 07 Apr, 2021

In this article, we are going to find the standard deviation of a column in a dataframe in R Programming Language.

To select the desired column of a dataframe $is used. Syntax: dataframe$column_name

Formula for variance:

where n is the total number of observations and x bar is the mean

Formula for standard deviation:

In the R programming language, for finding standard deviation on set of data, the method used is sd()

Syntax:

sd(data_values)

Where data-values are a vector input or data frame input.

Example 1:

 # data1 with vector of elements data1=c(1,2,3,4,5)   # data2 with vector of elements data2=c("sravan",'bobby','rohith','gnanu','ojaswi')   # give input to the data which is a dataframe data=data.frame(a1=data1,a2=data2)   # finding standard deviation of dataframe # column 1 print(sd(data$a1))  Output: [1] 1.581139 Example 2: ## R  # data1 with vector of elements data1=c(1,2,3,4,5)   # data2 with vector of elements data2=c(10,20,30,40,50)   # give input to the data which is a # dataframe data=data.frame(a1=data1,a2=data2)   # finding standard deviation of dataframe # column 1 print(sd(data$a1))   # finding standard deviation of dataframe # column 2 print(sd(data$a2))  Output: [1] 1.581139 [1] 15.81139 Example 3: ## R  # data1 with vector of elements (float # values) data1=c(1.0,2,3,4,5,8)   # data2 with vector of elements(float # values) data2=c(10,20.5,30.3,40,50,67.89)   # give input to the data which is a # dataframe data=data.frame(a1=data1,a2=data2)   # finding standard deviation of dataframe # column 1 print(sd(data$a1))   # finding standard deviation of dataframe  # column 2 print(sd(data\$a2))

Output:

[1] 2.483277

[1] 20.86387