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To create a column of square in data frames stored in R list, we can follow the below steps −First of all, create a list of data frames.Then, use lapply function to create a column of square in data frames stored in the list.ExampleCreate the list of data framesUsing data.frame function to create data frames and list function to create the list of those data frames −df1
To replace numerical column values based on character column values in R data frame, we can use subsetting with single square brackets and %in% operator and the value will be assigned with
If we have a data frame column that contains some duplicate values or represent categories then we might want to split the data frame based on that column.For example, if we have a data frame called df that contains a column say Col then we can split the data frame by Col by using the command given below −split(df,df$Col)Example 1Following snippet creates a sample data frame −Group
To create a column of division in data frames stored in R list, we can follow the below steps −First of all, create a list of data frames.Then, use lapply function to create a column of division in data frames stored in the list.ExampleCreate the list of data framesUsing data.frame function to create data frames and list function to create the list of those data frames −df1
To write text outside plot using ggplot2, we can use annotate function and coord_cartesian function. The annotate function will define the text value and the coord_cartesian function will define the position of the text outside the plot area.Check out the below example to understand how it works.ExampleFollowing snippet creates a sample data frame −x
To find the mean of multiple columns based on multiple grouping columns in R data frame, we can use summarise_at function with mean function.For Example, if we have a data frame called df that contains two grouping columns say G1 and G2 and two numerical columns say Num1 and Num2 then we can find the mean of Num1 and Num2 based on G1 and G2 by using the below mentioned command −df%%group_by(G1,G2)%%summarise_at(vars("Num1","Num2"),mean)Example 1Following snippet creates a sample data frame −Gender
To cut a data frame column with minimum value, we need to specify the minimum value withing cut function with the help of min function and set the include.lowest argument to TRUE. We can also specify the maximum value so that the maximum value is also taken into account while cutting the column.Example 1Following snippet creates a sample data frame −x
To create a column of difference in data frames stored in R list, we can follow the below steps −First of all, create a list of data frames.Then, use lapply function to create a column of difference in data frames stored in the list.ExampleCreate the list of data framesUsing data.frame function to create data frames and list function to create the list of those data frames −df1
To create a matrix with only one row in R, we can set the nrow argument of matrix function to 1.For example, if we want to create a matrix say M with only one row then it can be done by using the command given below −M
To combine two rows in data.table object in R by addition, we can follow the below steps −First of all, create a data.table object.Then, using plus sign (+) to add two rows and store the addition in one of the rows.After that, remove the row that is not required by subsetting with single square brackets.ExampleCreate the data.table objectLet’s create a data.table object as shown below: −library(data.table) x