Groupby minimum in R

Groupby minimum in R can be accomplished by aggregate() or group_by() function of dplyr package. Groupby minimum of multiple column and single column in R is accomplished by multiple ways some among them are group_by() function of dplyr package in R and aggregate() function in R.  Let’s see how to

  • Groupby min of single column in R
  • Groupby min of multiple columns in R
  • Groupby minimum using aggregate() function
  • Groupby minimum using group_by() function.

Groupby minimum in R and its functionality has been pictographically represented as shown below

Generic Groupby min 1

First let’s create a dataframe

df1= data.frame(Name=c('James','Paul','Richards','Marico','Samantha','Ravi','Raghu','Richards','George','Ema','Samantha','Catherine'),
    State=c('Alaska','California','Texas','North Carolina','California','Texas','Alaska','Texas','North Carolina','Alaska','California','Texas'),
    Sales=c(14,24,31,12,13,7,9,31,18,16,18,14))
df1

df1 will be

groupby min in R 1

Groupby using aggregate() syntax:

aggregate(x, by, FUN, …, simplify = TRUE, drop = TRUE)
X an R object, mostly a dataframe
by a list of grouping elements, by which the subsets are grouped by
FUN a function to compute the summary statistics
simplify a logical indicating whether results should be simplified to a vector or matrix if possible
drop a logical indicating whether to drop unused combinations of grouping values.

Groupby minimum of single column in R:

Method 1:

Aggregate function along with parameter by – by which it is to be grouped and function min is mentioned as shown below

# Groupby min of single column

aggregate(df1$Sales, by=list(df1$State), FUN=min)

so the grouped dataframe will be

groupby min in R 2a

Method 2: groupby using dplyr

group_by() function takes “state” column as argument  summarise() uses min() function to find minimum of sales.

library(dplyr)
df1 %>% group_by(State) %>% summarise(Min_sales = min(Sales))

so the grouped dataframe with minimum of sales calculated will be

groupby min in R 2b

 

 

Groupby minimum of multiple column in R:

Method 1:

Aggregate function which is grouped by “State” and “Name”, along with function min is mentioned as shown below

# Groupby min of multiple columns

aggregate(df1$Sales, by=list(df1$State,df1$Name), FUN=min)

so the grouped dataframe will be

groupby min in R 3a

Method 2: groupby using dplyr

group_by() function takes “State” and “Name” column as argument and groups by these two columns and summarise() uses min() function to find minimum of a sales.

library(dplyr)
df1 %>% group_by(State,Name) %>% summarise(Min_sales = min(Sales))

so the grouped dataframe will be

groupby min in R 3b

 

For further understanding of group_by() function in R using dplyr one can refer the dplyr documentation.


Related Topics:

                                                                                                     

Author

  • Sridhar Venkatachalam

    With close to 10 years on Experience in data science and machine learning Have extensively worked on programming languages like R, Python (Pandas), SAS, Pyspark.

    View all posts