# Groupby mean in R

Groupby mean in R can be accomplished by aggregate() or group_by() function of dplyr package. Groupby mean 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 mean of single column in R
• Groupby mean of multiple columns in R
• Groupby mean using aggregate() function
• Groupby mean using group_by() function.

Groupby mean and its functionality has been pictographically represented as shown below First let’s create a dataframe

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

df1 will be #### 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.

#### Method 1:

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

```# Groupby mean of single column

aggregate(df1\$Sales, by=list(df1\$State), FUN=mean)
```

so the grouped dataframe will be #### Method 2: groupby using dplyr

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

```library(dplyr)
df1 %>% group_by(State) %>% summarise(Mean_sales = mean(Sales))
```

so the grouped dataframe will be #### Method 1:

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

```# Groupby mean of multiple columns

aggregate(df1\$Sales, by=list(df1\$State,df1\$Name), FUN=mean)
```

so the grouped dataframe will be #### Method 2: groupby using dplyr

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

```library(dplyr)
df1 %>% group_by(State,Name) %>% summarise(Mean_sales = mean(Sales))
```

so the grouped dataframe by “State” and “Name” column with aggregated mean of sales will be For further understanding of group_by() function in R using dplyr one can refer the dplyr documentation.

## Author

• 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.